{"id":"CVE-2026-114620","title":"Authlib: Unvalidated request_uri fetch in JWT-secured authorization request (JAR) leading to SSRF","summary":"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…","severity":"medium","cvss":5.4,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","cvssSource":"cna","cwe":["CWE-918"],"vendor":"authlib","product":"authlib","affected":["authlib < 1.9.0"],"published":"2026-10-22","updated":"2026-10-22","sourceUpdated":"2026-10-22T21:34:11.909Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-114620","references":[{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8","label":"https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8"},{"url":"https://github.com/authlib/authlib/pull/949","label":"https://github.com/authlib/authlib/pull/949"},{"url":"https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0","label":"https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0"},{"url":"https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6","label":"https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6"},{"url":"https://github.com/authlib/authlib/releases/tag/v1.9.0","label":"https://github.com/authlib/authlib/releases/tag/v1.9.0"}],"tags":["cve.org"],"ingestedAt":"2026-10-22T22:00:50.450Z","slug":"CVE-2026-114620","body":"## Overview\n\nAuthlib 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.\n\n## Affected\n\n- `authlib < 1.9.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}