{"action":"Upgrade mcp to 1.27.2 or later.","affected":[{"fixed":"1.27.2","introduced":"0"}],"component":"mcp","cve_ids":["CVE-2026-52869"],"ecosystem":"PyPI","epss":0.00535,"exploited":false,"fixed_versions":["1.27.2"],"ghsa_id":"GHSA-jpw9-pfvf-9f58","id":"tcs_01M5KH5JZQ25AEKY39XK2J9KNN","modified_at":"2026-07-23T15:00:13.853115115Z","published_at":"2026-07-23T11:41:46.472358Z","references":["https://osv.dev/vulnerability/PYSEC-2026-3482","https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-jpw9-pfvf-9f58","https://nvd.nist.gov/vuln/detail/CVE-2026-52869","https://github.com/modelcontextprotocol/python-sdk/pull/2690","https://github.com/modelcontextprotocol/python-sdk/pull/2719","https://github.com/modelcontextprotocol/python-sdk/commit/1abcca2408a6b50e10ec601181f63f9978705c00","https://github.com/modelcontextprotocol/python-sdk/commit/ce267b6fc515dc4efc1dc70b6975b16ff0feef0a","https://github.com/modelcontextprotocol/python-sdk","https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.27.2","https://pypi.org/project/mcp","https://github.com/advisories/GHSA-jpw9-pfvf-9f58"],"severity":{"label":"high","score":7.1},"sources":[{"source":"osv","source_id":"PYSEC-2026-3482","url":"https://osv.dev/vulnerability/PYSEC-2026-3482"}],"summary":"MCP Python SDK: HTTP transports serve session requests without verifying the authenticated principal"}