Low-level GCM ignores the operation nonce

In all published versions of dcrypt-algorithms before 2.0.0, the low-level Gcm builder required an operation nonce but derived J0 from the nonce captured by the original Gcm constructor. Multiple operations could therefore silently reuse a nonce even when callers supplied distinct values,...

JLSEC-2026-749 HMAC zero-length tag forgery in `EVP_DigestVerifyFinal`, where a zero-length tag could be accepted...

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...

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

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

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 HMAC zero-length tag forgery in EVP_DigestVerifyFinal

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...

PYSEC-2018-52

A flaw was found in python-cryptography versions between =1.9.0 and 2.3. The finalizewithtag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalizewithtag an attacker could craft an invalid payload with a shortened tag e.g. 1 byte suc...