{"id":"CVE-2026-116684","published":"2026-10-27T20:17:13.307","lastModified":"2026-10-27T20:17:13.307","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.","cvssScore":6.8,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-863"],"vendors":[],"products":[],"references":[{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/3447","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/3451","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23","tags":[]}],"exploitRefs":[{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/3447","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/3451","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0","tags":[]},{"url":"https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23","tags":[]}],"hasPoc":true,"ai":null}