{"id":"CVE-2026-114616","published":"2026-10-22T22:18:04.420","lastModified":"2026-10-23T19:34:14.170","description":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.1, Authlib's OctKey.import_key() and HMAC signing and verification path accept zero-length key material. If an application's secret lookup can return an empty string or empty bytes, a remote attacker can compute the deterministic HS256, HS384, or HS512 signature for arbitrary token claims and have Authlib treat the token as authentic. This issue is fixed in version 1.9.1.","cvssScore":7.4,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-287","CWE-326","CWE-1391"],"vendors":[],"products":[],"references":[{"url":"https://github.com/authlib/authlib/commit/4ff30db442c70e29486e1982cb0ad37c037f5f4b","tags":[]},{"url":"https://github.com/authlib/authlib/releases/tag/v1.9.1","tags":[]},{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-8m4g-j4wp-wgcg","tags":[]}],"exploitRefs":[{"url":"https://github.com/authlib/authlib/commit/4ff30db442c70e29486e1982cb0ad37c037f5f4b","tags":[]},{"url":"https://github.com/authlib/authlib/releases/tag/v1.9.1","tags":[]},{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-8m4g-j4wp-wgcg","tags":[]}],"hasPoc":true,"ai":null}