{"id":"ALPINE-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":"2026-11-03T06:33:05.796257408Z","published":"2026-06-25T22:17:03.010Z","upstream":["CVE-2026-6331"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2026-6331"}],"affected":[{"package":{"name":"wolfssl","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/wolfssl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.15.5"},{"fixed":"5.9.2-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-6331.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}