{"id":"CVE-2026-114615","revision":"c700653983f24b9fa3bab210279070b5","records":[{"revision":"c700653983f24b9fa3bab210279070b5","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-114615","aliases":[],"title":"Authlib incomplete algorithm-confusion fix permits HMAC forgery with prefixed public keys","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.","state":0,"publishedAt":"2026-10-22T21:10:02.023+00:00","modifiedAt":"2026-10-22T21:10:02.023+00:00","affected":[{"ecosystem":"Vendor product","name":"authlib","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"authlib\",\n                    \"product\": \"authlib\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 1.3.1, < 1.9.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","score":7.4,"severity":"HIGH"}],"references":["https://github.com/authlib/authlib/security/advisories/GHSA-7vr2-2fgp-9w7p","https://github.com/authlib/authlib/pull/945","https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf","https://github.com/authlib/authlib/releases/tag/v1.9.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-114615","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-114615","identifiers":["CVE-2026-114615"]},"retained":false,"historicalAffected":[]}],"coverage":[]}