---
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'
---

## Overview

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

- `authlib < 1.9.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.