EUVD-2026-39565

HMAC zero-length tag forgery in EVPDigestVerifyFinal, 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...

CVE-2026-6331

CVE-2026-6331 describes a vulnerability in the OpenSSL-compatibility HMAC verify path where EVP_DigestVerifyFinal could accept a zero-length or truncated tag. The root cause is insufficient validation of the supplied signature length, which was only checked to not exceed the MAC length rather tha...