{"id":"CVE-2026-114620","state":"PUBLISHED","title":"Authlib: Unvalidated request_uri fetch in JWT-secured authorization request (JAR) leading to SSRF","description":"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.","publishedAt":"2026-10-22T21:34:11.909Z","updatedAt":"2026-10-30T20:14:29.752Z","severity":{"score":5.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["authlib authlib"],"affected":[{"vendor":"authlib","product":"authlib","versions":[{"version":"< 1.9.0","status":"affected"}]}],"references":["https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8","https://github.com/authlib/authlib/pull/949","https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0","https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6","https://github.com/authlib/authlib/releases/tag/v1.9.0"],"weaknesses":["CWE-918"],"ingestedAt":"2026-10-30T20:20:07.083Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/114xxx/CVE-2026-114620.json","commit":"00b08630266947671d4e9b6c8d071b69dbb66e11","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-114620","state":"PUBLISHED","datePublished":"2026-10-22T21:34:11.909Z","dateUpdated":"2026-10-30T20:14:29.752Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-21T20:34:25.600Z"},"containers":{"cna":{"title":"Authlib: Unvalidated request_uri fetch in JWT-secured authorization request (JAR) leading to SSRF","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"authlib","product":"authlib","versions":[{"version":"< 1.9.0","status":"affected"}]}],"references":[{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8","name":"https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/authlib/authlib/pull/949","name":"https://github.com/authlib/authlib/pull/949","tags":["x_refsource_MISC"]},{"url":"https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0","name":"https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0","tags":["x_refsource_MISC"]},{"url":"https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6","name":"https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6","tags":["x_refsource_MISC"]},{"url":"https://github.com/authlib/authlib/releases/tag/v1.9.0","name":"https://github.com/authlib/authlib/releases/tag/v1.9.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.4,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-22T21:34:11.909Z"},"source":{"advisory":"GHSA-x4rv-c3wx-4cr8","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-30T20:14:23.536072Z","id":"CVE-2026-114620","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-30T20:14:29.752Z"}}]}}}