{"id":"CVE-2026-114620","summary":"Authlib: Unvalidated request_uri fetch in JWT-secured authorization request (JAR) leading to SSRF","details":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, Authlib's RFC 9101 JWTAuthenticationRequest passes the unauthenticated, client-controlled request_uri parameter to the abstract get_request_object() hook before applying a destination or registration policy; the hook itself performs no network request, while the documentation demonstrates an unrestricted HTTP fetch. In deployments whose integrator implements that hook as an unrestricted outbound fetch, a remote attacker who knows a valid public client identifier can make the authorization server request internal, link-local, or otherwise unintended URLs and can distinguish fetch outcomes through different error responses and timing. Deployments whose custom hook already applies a secure allowlist, destination controls, and retrieval limits are not affected. The JWTAuthenticationRequest implementation in authlib/oauth2/rfc9101/authorization_server.py forwards request_uri to get_request_object() before an application-approved retrieval policy accepts the destination. This issue is fixed in version 1.9.0.","aliases":["GHSA-x4rv-c3wx-4cr8","PYSEC-2026-4360"],"modified":"2026-11-01T02:30:35.183437533Z","published":"2026-10-22T21:34:11.909Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-918"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114620.json"},"references":[{"type":"WEB","url":"https://github.com/authlib/authlib/releases/tag/v1.9.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114620.json"},{"type":"ADVISORY","url":"https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-114620"},{"type":"FIX","url":"https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0"},{"type":"FIX","url":"https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6"},{"type":"FIX","url":"https://github.com/authlib/authlib/pull/949"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/authlib/authlib","events":[{"introduced":"fe87a117f941975793bf4063e9b08b90e88b230a"},{"fixed":"e8d50bd7dc442fde1364291df9c429d1da91c0cb"},{"fixed":"6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0"},{"fixed":"891e3f10ae5989176211f8be35dcc7cd40aa92c6"}],"database_specific":{"extracted_events":[{"source":"CPE_RANGE","cpe":"cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:*","range":[{"introduced":"1.6.0"},{"fixed":"1.9.0"}]},{"source":"REFERENCES_COMMIT","range":[{"fixed":"6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0"}]},{"source":"REFERENCES_COMMIT","range":[{"fixed":"891e3f10ae5989176211f8be35dcc7cd40aa92c6"}]},{"range":[{"fixed":"e8d50bd7dc442fde1364291df9c429d1da91c0cb"}],"source":"REFERENCES_TAG","original_tag":"v1.9.0"}]}}],"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"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-114620.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N"}]}