{"action":"Upgrade mcp to 1.28.1 or later.","affected":[{"fixed":"1.28.1","introduced":"0"}],"component":"mcp","cve_ids":["CVE-2026-59950"],"ecosystem":"PyPI","epss":0.00231,"exploited":false,"fixed_versions":["1.28.1"],"ghsa_id":"GHSA-vj7q-gjh5-988w","id":"tcs_01M5KH5K44BM2JNZ4657HQ7GF1","modified_at":"2026-07-23T15:00:13.898863418Z","published_at":"2026-07-23T11:41:46.534440Z","references":["https://osv.dev/vulnerability/PYSEC-2026-3483","https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-vj7q-gjh5-988w","https://nvd.nist.gov/vuln/detail/CVE-2026-59950","https://github.com/modelcontextprotocol/python-sdk/pull/2992","https://github.com/modelcontextprotocol/python-sdk/commit/777b8d06710c140e3606b0d4598e2aa48546c266","https://github.com/modelcontextprotocol/python-sdk","https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.28.1","https://pypi.org/project/mcp","https://github.com/advisories/GHSA-vj7q-gjh5-988w"],"severity":{"label":"high","score":8.1},"sources":[{"source":"osv","source_id":"PYSEC-2026-3483","url":"https://osv.dev/vulnerability/PYSEC-2026-3483"},{"source":"nvd","source_id":"CVE-2026-59950","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59950"}],"summary":"MCP Python SDK: WebSocket server transport does not support Host/Origin validation"}