{"id":"CVE-2026-114615","published":"2026-10-22T22:18:04.257","lastModified":"2026-10-23T19:34:14.170","description":"Authlib is a Python library which builds OAuth and OpenID Connect servers. From 1.3.1 until 1.9.0, OctKey.import_key() checks asymmetric-key markers only at byte zero while Authlib's PEM loaders accept leading whitespace, comments, or a byte-order mark. In deployments that use the documented mixed algorithm registry and already configure verification with PEM or certificate bytes containing such a prefix, an unauthenticated attacker who knows those same public-key bytes can use them as an HMAC secret and forge HS256 tokens with arbitrary identity or authorization claims. This is a bypass of the remediation for CVE-2024-37568. The module-level jwt object reaches OctKey.import_key() in authlib/jose/rfc7518/oct_key.py, where POSSIBLE_UNSAFE_KEYS fails to identify prefixed asymmetric key material. This issue is fixed in version 1.9.0.","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-184","CWE-347"],"vendors":[],"products":[],"references":[{"url":"https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf","tags":[]},{"url":"https://github.com/authlib/authlib/pull/945","tags":[]},{"url":"https://github.com/authlib/authlib/releases/tag/v1.9.0","tags":[]},{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p","tags":[]}],"exploitRefs":[{"url":"https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf","tags":[]},{"url":"https://github.com/authlib/authlib/pull/945","tags":[]},{"url":"https://github.com/authlib/authlib/releases/tag/v1.9.0","tags":[]},{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p","tags":[]}],"hasPoc":true,"ai":null}