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...

Linux Distros Unpatched Vulnerability : CVE-2026-6331

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - HMAC zero-length tag forgery in EVPDigestVerifyFinal, where a zero-length tag could be accepted as valid during HMAC verification. In the OpenSSL-compatibility...

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...

DEBIAN-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...

UBUNTU-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...

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...

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...

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

CVE-2026-6331 describes an HMAC zero-length tag forgery in EVP_DigestVerifyFinal. The OpenSSL-compatibility HMAC verify path allowed a zero-length or truncated tag to pass because the signature length check only ensured it did not exceed the MAC length. The fixed behavior now requires the supplie...

PT-2026-52604

Name of the Vulnerable Software and Affected Versions The product name cannot be determined affected versions not specified Description An issue exists in the EVP DigestVerifyFinal function where a zero-length tag could be accepted as valid during HMAC Hash-based Message Authentication Code...