modelcontextprotocol python-sdk vulnerabilities

CVEs per yearBy the year they were published

1. 20253
2. 20268

Newest CVEs

• CVE-2026-116686

  Model Context Protocol Python SDK: Client fetched server-chosen $ref URLs while validating tool results against output schemas

  modelcontextprotocol · python-sdk

  Medium6.5
• CVE-2026-116685

  Model Context Protocol Python SDK: HTTP client transports followed cross-origin redirects carrying custom headers and bodies

  modelcontextprotocol · python-sdk

  Medium5.9
• CVE-2026-116684

  Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource server

  modelcontextprotocol · python-sdk

  Medium6.8
• CVE-2026-109527

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

  modelcontextprotocol · python-sdk

  High7.5
• CVE-2026-59951

  MCP Python SDK: Unbounded Session Accumulation in StreamableHTTP Transport Enables Resource Exhaustion

  modelcontextprotocol · python-sdk

  Medium6.9
• CVE-2026-59950

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

  modelcontextprotocol · python-sdk

  High7.6
• CVE-2026-52870

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

  modelcontextprotocol · python-sdk

  High7.6
• CVE-2026-52869

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

  modelcontextprotocol · python-sdk

  High7.1
• CVE-2025-66416

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

  modelcontextprotocol · python-sdk

  High7.6
• CVE-2025-53366

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

  modelcontextprotocol · python-sdk

  High8.7