MCP Python SDK vulnerabilities and CVEs
The Beam CVE database tracks 7 security advisories for MCP Python SDK: 6 high and 1 medium severity. The newest is CVE-2026-59951, published Oct 15, 2026 and fixed in 1.30.0, 2.2.0.
The official Python SDK for building MCP servers and clients.
Check your version: pip show mcp
- Vulnerabilities tracked
- 7
- Critical
- 0
- Known exploited (CISA KEV)
- 0
- Published in the last 30 days
- 1
All entries, newest first
CVE-2026-59951
MCP Python SDK: Unbounded Session Accumulation in StreamableHTTP Transport Enables Resource Exhaustion
medium7.5Oct 15, 2026CVE-2026-52869
MCP Python SDK: HTTP transports serve session requests without verifying the authenticated principal
high7.1Jul 16, 2026CVE-2026-52870
MCP Python SDK: Experimental task handlers allow any client to access and cancel other clients' tasks
high7.6Jul 16, 2026CVE-2026-59950
MCP Python SDK: WebSocket server transport does not support Host/Origin validation
high7.6Jul 16, 2026CVE-2025-66416
Model Context Protocol (MCP) Python SDK does not enable DNS rebinding protection by default
high7.6Dec 2, 2025CVE-2025-53365
MCP Python SDK has Unhandled Exception in Streamable HTTP Transport, Leading to Denial of Service
high8.7Jul 4, 2025CVE-2025-53366
MCP Python SDK vulnerability in the FastMCP Server causes validation error, leading to DoS
high8.7Jul 4, 2025