CVE-2026-75803 (GCVE-0-2026-75803)

Vulnerability from cvelistv5 – Published: 2026-08-25 13:00 – Updated: 2026-09-01 18:23
VLAI
Title
AEAD Forgeries with Empty Ciphertext When Using EVP_Cipher()
Summary
Issue summary: ChaCha20-Poly1305 and AES-OCB decryption with an empty ciphertext can report success without verifying the supplied authentication tag when the operation is finalized by calling the EVP_Cipher() function. Impact summary: Applications calling EVP_Cipher() on an empty ciphertext and expecting the call to check the AEAD tag may accept forged messages. CWE: CWE-354 (Improper Validation of Integrity Check Value) Description: The EVP_Cipher() API call for AEAD ciphers behaves like a one shot encryption and decryption call. It also verifies the AEAD tag after the decryption operation. However for AES-OCB and ChaCha20-Poly1305 ciphers it skipped the AEAD tag verification when an empty ciphertext was passed to the function. The callers of this function might believe that a successful return indicates a valid AEAD tag for these ciphers, even when that has not truly been validated in this case. FIPS impact: no The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this CVE as the affected algorithms are not FIPS approved and thus not implemented in the FIPS module.
Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-01 18:22 UTC
CWE
  • CWE-354 - Improper Validation of Integrity Check Value
Assigner
References
Impacted products
Vendor Product Version
OpenSSL OpenSSL Affected: 4.0.0 , < 4.0.2 (semver)
Affected: 3.6.0 , < 3.6.4 (semver)
Affected: 3.5.0 , < 3.5.8 (semver)
Affected: 3.4.0 , < 3.4.7 (semver)
Affected: 3.0.0 , < 3.0.22 (semver)
Create a notification for this product.
Date Public
2026-08-25 15:57
Credits
Billy Brumley (Rochester Institute of Technology) Billy Brumley (Rochester Institute of Technology)
Show details on NVD website
To clipboard 

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