Vulnerability-Lookup

URL	Tags
https://github.com/urllib3/urllib3/security/advis…	x_refsource_CONFIRM
https://github.com/urllib3/urllib3/commit/ea2ad7b…	x_refsource_MISC
https://github.com/urllib3/urllib3/releases/tag/2.8.0	x_refsource_MISC

Vendor	Product	Version
urllib3	urllib3	Affected: >= 2.6.2, < 2.8.0

BREW-ABI3AUDIT-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 20:28 – Updated: 2026-10-02 10:17 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.8.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "abi3audit",
        "purl": "pkg:brew/abi3audit"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.25_1"
            },
            {
              "fixed": "0.0.26_5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.8.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.8.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-abi3audit-CVE-2026-97688",
  "modified": "2026-10-02T10:17:56Z",
  "published": "2026-09-30T20:28:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688",
    "PYSEC-2026-4176"
  ]
}

BREW-AIDER-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 19:59 – Updated: 2026-10-02 09:56 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": null,
        "range_state": "affected",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.6.3",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "aider",
        "purl": "pkg:brew/aider"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.86.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.6.3",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.6.3"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-aider-CVE-2026-97688",
  "modified": "2026-10-02T09:56:23Z",
  "published": "2026-09-30T19:59:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688",
    "PYSEC-2026-4176"
  ]
}

BREW-AIVEN-CLIENT-CVE-20… (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 20:02 – Updated: 2026-10-02 10:08 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.8.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "aiven-client",
        "purl": "pkg:brew/aiven-client"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.11.0_2"
            },
            {
              "fixed": "4.18.0_1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.8.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.8.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-aiven-client-CVE-2026-97688",
  "modified": "2026-10-02T10:08:51Z",
  "published": "2026-09-30T20:02:49Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688",
    "PYSEC-2026-4176"
  ]
}

BREW-ANSIBLE-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 18:44 – Updated: 2026-10-02 08:50 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.8.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "ansible",
        "purl": "pkg:brew/ansible"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "13.2.0_2"
            },
            {
              "fixed": "14.4.0_1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.8.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.8.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-ansible-CVE-2026-97688",
  "modified": "2026-10-02T08:50:21Z",
  "published": "2026-09-30T18:44:09Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688",
    "PYSEC-2026-4176"
  ]
}

BREW-ANSIBLE@13-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 21:01 – Updated: 2026-09-30 21:01 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.8.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "ansible@13",
        "purl": "pkg:brew/ansible%4013"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "13.7.0"
            },
            {
              "fixed": "13.8.0_3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.8.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.8.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-ansible@13-CVE-2026-97688",
  "modified": "2026-09-30T21:01:57Z",
  "published": "2026-09-30T21:01:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688"
  ]
}

BREW-APM-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 19:22 – Updated: 2026-10-02 09:15 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.8.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "apm",
        "purl": "pkg:brew/apm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.26.0"
            },
            {
              "fixed": "0.31.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.8.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.8.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-apm-CVE-2026-97688",
  "modified": "2026-10-02T09:15:04Z",
  "published": "2026-09-30T19:22:38Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688",
    "PYSEC-2026-4176"
  ]
}

BREW-APPRISE-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 18:59 – Updated: 2026-10-02 09:05 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.8.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "apprise",
        "purl": "pkg:brew/apprise"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.9.6_1"
            },
            {
              "fixed": "2.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.8.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.8.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-apprise-CVE-2026-97688",
  "modified": "2026-10-02T09:05:54Z",
  "published": "2026-09-30T18:59:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688",
    "PYSEC-2026-4176"
  ]
}

BREW-ARCHGW-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 18:44 – Updated: 2026-10-02 08:49 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.8.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "archgw",
        "purl": "pkg:brew/archgw"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.3.22"
            },
            {
              "fixed": "0.3.22_5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.8.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.8.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-archgw-CVE-2026-97688",
  "modified": "2026-10-02T08:49:47Z",
  "published": "2026-09-30T18:44:11Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688",
    "PYSEC-2026-4176"
  ]
}

BREW-ARJUN-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 20:45 – Updated: 2026-10-02 10:40 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.8.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "arjun",
        "purl": "pkg:brew/arjun"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.2.7_4"
            },
            {
              "fixed": "2.2.7_8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.8.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.8.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-arjun-CVE-2026-97688",
  "modified": "2026-10-02T10:40:27Z",
  "published": "2026-09-30T20:45:59Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688",
    "PYSEC-2026-4176"
  ]
}

BREW-AWS-SAM-CLI-CVE-202… (GHSA-GH4C-6FX4-QH6G)

Vulnerability from osv_homebrew – Published: 2026-09-30 21:02 – Updated: 2026-09-30 21:02 – Source website

Summary

urllib3: Chunked Deflate streaming can enter an infinite loop

Details

Impact

urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.

urllib3 can decompress response bodies according to the HTTP Content-Encoding header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.

However, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python's zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.

A malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.

Affected usages

Applications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:

Compressed responses from an untrusted source are streamed using HTTPResponse.stream(amt=N) or HTTPResponse.read_chunked(amt=N) with a positive, finite chunk size.
Content decoding is enabled.
The response uses both Transfer-Encoding: chunked and Content-Encoding: deflate.
The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.

HTTPResponse.stream() uses a finite chunk size by default and is therefore affected when the other conditions are met.

Remediation

Upgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.

If upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting decode_content=False, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.

Severity

6.9 (Medium)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

URL

Type

	https://github.com/urllib3/urllib3/security/advis…	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-97688	ADVISORY
	https://github.com/urllib3/urllib3/commit/ea2ad7b…	WEB
	https://github.com/urllib3/urllib3	PACKAGE
	https://github.com/urllib3/urllib3/releases/tag/2.8.0	WEB

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": null,
        "range_state": "affected",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.7.0",
        "upstream_fixed_in": "2.8.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "aws-sam-cli",
        "purl": "pkg:brew/aws-sam-cli"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.151.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.7.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.7.0"
      }
    ]
  },
  "details": "### Impact\n\nurllib3\u0027s streaming API is designed for the efficient handling of large HTTP responses by reading content in chunks instead of loading the entire response body into memory at once.\n\nurllib3 can decompress response bodies according to the HTTP `Content-Encoding` header. When streaming a compressed, chunked response, urllib3 first consumes data already buffered by the decoder before reading the next HTTP chunk.\n\nHowever, urllib3 versions from 2.6.2 through 2.7.0 could enter an infinite loop when a chunked response contained bytes after the end of the Deflate stream. If the decompressed body exceeded the requested streaming chunk size, Python\u0027s zlib implementation could retain the trailing bytes as unconsumed input after reaching the end of the compressed stream. urllib3 would repeatedly attempt to decode those same bytes without making progress or reading more data from the network.\n\nA malicious server could exploit this behavior to cause excessive CPU usage and prevent the affected request from completing on the client. Network read timeouts would not interrupt the loop because no further socket operation was required.\n\n### Affected usages\n\nApplications and libraries using urllib3 versions 2.6.2 through 2.7.0 may be affected when all of the following conditions are met:\n\n1. Compressed responses from an untrusted source are streamed using `HTTPResponse.stream(amt=N)` or `HTTPResponse.read_chunked(amt=N)` with a positive, finite chunk size.\n2. Content decoding is enabled.\n3. The response uses both `Transfer-Encoding: chunked` and `Content-Encoding: deflate`.\n4. The decoded body exceeds the requested chunk size and the encoded body contains bytes after the end of the Deflate stream.\n\n`HTTPResponse.stream()` uses a finite chunk size by default and is therefore affected when the other conditions are met.\n\n### Remediation\n\nUpgrade to urllib3 2.8.0, in which the Deflate decoder stops accepting input after reaching the end of the compressed stream and no longer reports trailing bytes as data that can produce more decoded output.\n\nIf upgrading is not immediately possible, disable automatic content decoding for responses from untrusted sources by setting `decode_content=False`, or reject streamed responses using the Deflate content encoding. Applications that disable automatic decoding must handle the compressed response safely at another layer.",
  "id": "BREW-aws-sam-cli-CVE-2026-97688",
  "modified": "2026-09-30T21:02:14Z",
  "published": "2026-09-30T21:02:14Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gh4c-6fx4-qh6g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97688"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/ea2ad7b21a80da3632f80016526a18864586077f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: Chunked Deflate streaming can enter an infinite loop",
  "upstream": [
    "GHSA-gh4c-6fx4-qh6g",
    "CVE-2026-97688"
  ]
}

CVE-2026-97688 (GCVE-0-2026-97688)

Tags

Sightings

Nomenclature

Related by attack behaviour

Action not permitted

CVE-2026-97688 (GCVE-0-2026-97688)

BREW-ABI3AUDIT-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-AIDER-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-AIVEN-CLIENT-CVE-20… (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-ANSIBLE-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-ANSIBLE@13-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-APM-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-APPRISE-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-ARCHGW-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-ARJUN-CVE-2026-97688 (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

BREW-AWS-SAM-CLI-CVE-202… (GHSA-GH4C-6FX4-QH6G)

Impact

Affected usages

Remediation

Tags

Sightings

Nomenclature

Related by attack behaviour