{"schema":"threatline.record/2","record":{"id":"CVE-2026-114618","aliases":["GHSA-fch4-3c6x-j4gc"],"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.","categories":["Unclassified"],"product":"authlib","vendor":"authlib","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-114618","source_modified_at":"2026-10-22T21:28:37.879Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"authlib","vendor":"authlib","versions":[{"version":"< 1.9.0","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":6.8,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00225,"percentile":0.1243,"score_date":"2026-10-23"},"published_at":"2026-10-22T21:28:37.879Z","modified_at":"2026-10-22T21:28:37.879Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-114618","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-22T21:28:37.879Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-114618","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/authlib/authlib/security/advisories/GHSA-fch4-3c6x-j4gc","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/authlib/authlib/pull/945","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/authlib/authlib/commit/e3bd41cb29dcfee434453b135ffb487884baeedf","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/authlib/authlib/releases/tag/v1.9.0","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-22T21:28:37.879Z","content_hash":"a22360083edd3a97a60f16c71255e4d6b37f674030d62e9722f6e48dc34613cb"}}