CVE-2026-116672

Full vulnerability record from the local CVENow database.

Description

Authlib is a Python library which builds OAuth and OpenID Connect servers. From 0.15 until 1.9.1, the documented ClientConfigurationEndpoint.authenticate_client and ClientConfigurationEndpoint.check_permission reference implementations look up a target client from request-controlled client_id data and check only whether that target is editable, without verifying that request.credential belongs to the target client. Deployments following both examples can allow a client holding any valid registration access token to read, modify, or delete another client's registration. Changing redirect_uris can enable authorization code or token interception, while deleting registrations can deny service to affected clients. This issue is fixed in version 1.9.1.

Severity

HIGH

CVSS score

8.8 (v3.1)

Vulnerability status

Awaiting Analysis

Source identifier

[email protected]

Published

2026-10-27 17:16:59.140000

Last modified

2026-10-27 21:31:20.100000

View original CVE JSON

{
  "id": "CVE-2026-116672",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-27T17:16:59.140",
  "lastModified": "2026-10-27T21:31:20.100",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Authlib is a Python library which builds OAuth and OpenID Connect servers. From 0.15 until 1.9.1, the documented ClientConfigurationEndpoint.authenticate_client and ClientConfigurationEndpoint.check_permission reference implementations look up a target client from request-controlled client_id data and check only whether that target is editable, without verifying that request.credential belongs to the target client. Deployments following both examples can allow a client holding any valid registration access token to read, modify, or delete another client's registration. Changing redirect_uris can enable authorization code or token interception, while deleting registrations can deny service to affected clients. This issue is fixed in version 1.9.1."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "authlib",
          "product": "authlib",
          "versions": [
            {
              "version": ">= 0.15, < 1.9.1",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-639"
        },
        {
          "lang": "en",
          "value": "CWE-1188"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/authlib/authlib/commit/1bd2a313492ce0a4d0571c150730907aa3fc91ff",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/authlib/authlib/releases/tag/v1.9.1",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/authlib/authlib/security/advisories/GHSA-c73q-w75p-j82v",
      "source": "[email protected]"
    }
  ]
}