{"id":"CVE-2026-114618","summary":"Authlib: Default JWT bearer grant accepts assertions for the wrong audience","details":"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.","aliases":["GHSA-fch4-3c6x-j4gc"],"modified":"2026-10-23T10:45:21.612340006Z","published":"2026-10-22T21:28:37.879Z","database_specific":{"cwe_ids":["CWE-1188","CWE-287"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114618.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114618.json"},{"type":"FIX","url":"https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf"},{"type":"FIX","url":"https://github.com/authlib/authlib/pull/945"},{"type":"WEB","url":"https://github.com/authlib/authlib/releases/tag/v1.9.0"},{"type":"ADVISORY","url":"https://github.com/authlib/authlib/security/advisories/GHSA-fch4-3c6x-j4gc"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-114618"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/authlib/authlib","events":[{"introduced":"0"},{"fixed":"e8d50bd7dc442fde1364291df9c429d1da91c0cb"},{"fixed":"e3bd41cb29dcfee434453b135ffb487884baeedf"}],"database_specific":{"extracted_events":[{"strategy":"StringRangeExpression","range":[{"introduced":"0"},{"fixed":"1.9.0"}],"source":"AFFECTED_FIELD"},{"source":"REFERENCES_COMMIT","range":[{"fixed":"e3bd41cb29dcfee434453b135ffb487884baeedf"}]},{"source":"REFERENCES_TAG","original_tag":"v1.9.0","range":[{"fixed":"e8d50bd7dc442fde1364291df9c429d1da91c0cb"}]}]}}],"versions":["v1.8.0","v1.7.2","v1.7.1","1.7.1","v1.7.0","v1.6.6","v1.6.5","v1.6.4","v1.6.3","v1.6.2","v1.6.1","v1.6.0","v1.5.2","v1.5.1","v1.5.0","v1.4.1","v1.4.0","v1.3.2","v1.3.0","v1.2.1","v1.2.0","v1.1.0","v1.0.1","v1.0.0","v0.15","v0.14.3","v0.14.2","v0.14.1","v0.14","v0.13","v0.12","v0.11","v0.10","v0.9","v0.8","v0.7","v0.6","v0.5.1","v0.5","v0.4.1","v0.4","v0.3","v0.2.1","v0.2","v0.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-114618.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"}]}