{"action":"Upgrade mcp to 1.30.0 or later.","affected":[{"fixed":"1.30.0","introduced":"1.8.0"},{"fixed":"2.2.0","introduced":"2.0.0"}],"component":"mcp","cve_ids":["CVE-2026-59951"],"ecosystem":"PyPI","exploited":false,"fixed_versions":["1.30.0","2.2.0"],"ghsa_id":"GHSA-84m7-p3x7-pcfv","id":"tcs_01M5JHGN9E33MQ318W5RVNBW0W","modified_at":"2026-10-15T20:30:08.565001293Z","published_at":"2026-10-15T20:13:13Z","references":["https://osv.dev/vulnerability/GHSA-84m7-p3x7-pcfv","https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-84m7-p3x7-pcfv","https://nvd.nist.gov/vuln/detail/CVE-2026-59951","https://github.com/modelcontextprotocol/python-sdk/pull/3395","https://github.com/modelcontextprotocol/python-sdk/pull/3426","https://github.com/modelcontextprotocol/python-sdk/commit/92120b4b0f50385af096592d7cee932fc1d994e7","https://github.com/modelcontextprotocol/python-sdk/commit/d2290ca3434731b68ea3e2270bc06a6e6575931b","https://github.com/modelcontextprotocol/python-sdk","https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0","https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0"],"severity":{"label":"high","score":7.5},"sources":[{"source":"osv","source_id":"GHSA-84m7-p3x7-pcfv","url":"https://osv.dev/vulnerability/GHSA-84m7-p3x7-pcfv"}],"summary":"MCP Python SDK: Unbounded Session Accumulation in StreamableHTTP Transport Enables Resource Exhaustion"}