CVE-2026-59950

The MCP Python SDK (package name mcp on PyPI) contains a vulnerability in the deprecated mcp.server.websocket.websocket_server transport prior to version 1.28.1, which accepted WebSocket handshakes without Host or Origin header validation. This prevents restrictions on originating connections to ...

CVE-2026-52869

The MCP Python SDK (mcp on PyPI) has a vulnerability affecting versions prior to 1.27.2 in its SSE and stateful Streamable HTTP transports. These transports (mcp.server.sse.SseServerTransport and mcp.server.streamable_http_manager.StreamableHTTPSessionManager) route requests to an existing sessio...

CVE-2025-66416

CVE-2025-66416 affects the MCP Python SDK (PyPI package mcp) prior to 1.23.0. It does not enable DNS rebinding protection by default for HTTP-based MCP servers. When run on localhost without authentication (e.g., with FastMCP, streamable HTTP or SSE transport) and without TransportSecuritySetting...