{"id":"CVE-2026-114618","published":"2026-10-22T22:18:04.747","lastModified":"2026-10-23T19:34:14.170","description":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, the default RFC 7523 JWTBearerGrant.get_audiences() returns an empty list, causing JWTBearerGrant.verify_claims() to require only that an aud claim exists without matching the current authorization server. An attacker holding a legitimate assertion for another service can present it to a server that shares the signing key and uses the default grant, obtaining an access token across a trust boundary. Implementations that override get_audiences() with the server's valid audience identifiers are not affected. This issue is fixed in version 1.9.0.","cvssScore":6.8,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-287","CWE-1188"],"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-fch4-3c6x-j4gc","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-fch4-3c6x-j4gc","tags":[]}],"hasPoc":true,"ai":null}