{"id":"CVE-2026-116672","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-116672","generatedAt":"2026-10-27T23:59:01.853Z","title":"Deployments following both examples can allow a client holding any valid registration access token to read, modify, or delete another client's registration.","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.","published":"2026-10-27T17:16:59.000Z","lastModified":"2026-10-27T21:31:20.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-639","CWE-1188"],"affected":[],"epss":null,"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unscored. Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-27T17:16:59.000Z","detail":{"score":"8.8","severity":"HIGH","publishedAt":"2026-10-27T17:16:59.140Z"},"summary":"New CVE, high severity (CVSS 8.8)."}],"references":[{"url":"https://github.com/authlib/authlib/commit/1bd2a313492ce0a4d0571c150730907aa3fc91ff","source":"security-advisories@github.com"},{"url":"https://github.com/authlib/authlib/releases/tag/v1.9.1","source":"security-advisories@github.com"},{"url":"https://github.com/authlib/authlib/security/advisories/GHSA-c73q-w75p-j82v","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-116672","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}