{"id":"DEBIAN-CVE-2026-6331","details":"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.","modified":"2026-09-14T17:03:47.260485383Z","published":"2026-06-25T22:17:03.010Z","upstream":["CVE-2026-6331"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-6331"}],"affected":[{"package":{"name":"wolfssl","ecosystem":"Debian:12","purl":"pkg:deb/debian/wolfssl?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.5.4-2+deb12u3"}]}],"versions":["5.5.4-2","5.5.4-2+deb12u1","5.5.4-2+deb12u2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-6331.json"}},{"package":{"name":"wolfssl","ecosystem":"Debian:13","purl":"pkg:deb/debian/wolfssl?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.7.2-0.1+deb13u2"}]}],"versions":["5.7.2-0.1","5.7.2-0.1+deb13u1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-6331.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}