CVE-2026-54504: MCP Documentation Server Web UI exposes unauthenticated document API

Summary

MCP Documentation Server versions 1.13.0 through 1.13.1 start a Web UI by default on port 3080, and startWebServer in src/web-server.ts calls app.listen(PORT) without a host, binding the unauthenticated document-management API to all interfaces instead of localhost. A network-reachable client can call endpoints such as GET /api/documents, POST /api/documents, DELETE /api/documents/:id and POST /api/search-all without credentials to read, search, insert or delete documents and alter the assistant's knowledge base. The attacker must be able to reach the service over a LAN, VM network, container bridge, VPN or other routed network, and the issue does not grant remote code execution.

Mitigation

Fixed in 1.13.1.

Topics

• AI agents
• Model Context Protocol

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