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Product · modelcontextprotocol

python-sdk

11 known vulnerabilities.

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  • High 7.5
    CVE-2026-109527

    Model Context Protocol Python SDK HTTP and OAuth endpoints allow memory exhaustion through unbounded request bodies

    The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. In mcp versions before 1.29.1 and from 2.0.0a1 through 2.0.1, the Streamable HTTP session manager, SSE message endpoint, and OAuth authorization-s…

    modelcontextprotocol python-sdk
  • High 7.6
    CVE-2026-59950

    MCP Python SDK: WebSocket server transport does not support Host/Origin validation

    The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to 1.28.1, the deprecated mcp.server.websocket.websocket_server transport accepted WebSocket handshakes without applying Host or Origin header valida…

    modelcontextprotocol python-sdk mcp PyPI
  • High 7.6
    CVE-2026-52870

    MCP Python SDK: Experimental task handlers allow any client to access and cancel other clients' tasks

    The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). From 1.23.0 until 1.27.2, default handlers installed by server.experimental.enable_tasks() for tasks/list, tasks/get, tasks/result, and tasks/cancel operat…

    modelcontextprotocol python-sdk mcp PyPI
  • High 7.1
    CVE-2026-52869

    MCP Python SDK: HTTP transports serve session requests without verifying the authenticated principal

    The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to 1.27.2, the SSE and stateful Streamable HTTP transports mcp.server.sse.SseServerTransport and mcp.server.streamable_http_manager.StreamableHTTPSes…

    modelcontextprotocol python-sdk mcp PyPI
  • High 7.6
    CVE-2025-66416

    DNS Rebinding Protection Disabled by Default in Model Context Protocol Python SDK for Servers Running on Localhost

    The MCP Python SDK, called `mcp` on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.23.0, tThe Model Context Protocol (MCP) Python SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an…

    modelcontextprotocol python-sdk mcp PyPI
  • High 8.7
    CVE-2025-53366

    MCP SDK Vulnerable to FastMCP Server Validation Error, Leading to Denial of Service

    The MCP Python SDK, called `mcp` on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.9.4, a validation error in the MCP SDK can cause an unhandled exception when processing malformed requests, resulting in service unava…

    modelcontextprotocol python-sdk mcp PyPI
  • High 8.7
    CVE-2025-53365

    MCP Python SDK has Unhandled Exception in Streamable HTTP Transport ,Leading to Denial of Service

    The MCP Python SDK, called `mcp` on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.10.0, if a client deliberately triggers an exception after establishing a streamable HTTP session, this can lead to an uncaught Closed…

    modelcontextprotocol python-sdk mcp PyPI