{"id":"CVE-2026-116684","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-116684","generatedAt":"2026-10-27T23:50:58.993Z","title":"The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients.","description":"The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.10.0 until 1.30.0 and 2.2.0, server-side bearer authentication configured through AuthSettings with token_verifier accepts a valid token issued for another service when the authorization server serves multiple resources and the TokenVerifier does not independently validate the aud audience. This resource-confusion flaw lets a token holder authenticate to the wrong MCP server and exercise that token's resulting access. This issue is fixed in versions 1.30.0 and 2.2.0.","published":"2026-10-27T20:17:13.000Z","lastModified":"2026-10-27T20:17:13.000Z","status":"Received","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"},"cwe":["CWE-863"],"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":"low","text":"Lower severity and no EPSS score yet. Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-27T20:17:13.000Z","detail":{"score":"6.8","severity":"MEDIUM","publishedAt":"2026-10-27T20:17:13.307Z"},"summary":"New CVE, medium severity (CVSS 6.8)."}],"references":[{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/3447","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/3451","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-116684","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."}