CVE-2026-6331 (GCVE-0-2026-6331)

Vulnerability from cvelistv5 – Published: 2026-06-25 20:56 – Updated: 2026-06-26 13:53
VLAI
Title
HMAC zero-length tag forgery in EVP_DigestVerifyFinal
Summary
HMAC zero-length tag forgery in EVP_DigestVerifyFinal, where a zero-length tag could be accepted as valid during HMAC verification. In the OpenSSL-compatibility HMAC verify path the supplied signature length was only checked as not exceeding the MAC length, so a zero-length or otherwise truncated tag could pass verification. The fix requires the supplied tag length to exactly equal the MAC length and rejects a zero-length MAC, so a forged short or empty tag is no longer accepted.
Severity
2.1 (Low)
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-26 13:52 UTC
CWE
  • CWE-347 - Improper Verification of Cryptographic Signature
Assigner
References
Impacted products
Vendor Product Version
wolfSSL wolfSSL Affected: 3.15.5 , ≤ 5.9.1 (semver)
Create a notification for this product.
Credits
Nicholas Carlini from Anthropic
Show details on NVD website
To clipboard 

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