n8n-mcp has unauthenticated session termination and information disclosure in HTTP transport

Summary

Several HTTP transport endpoints in n8n-mcp lacked proper authentication, and the health check endpoint exposed sensitive operational metadata without credentials.

Impact

An unauthenticated attacker with network access to the n8n-mcp HTTP server could disrupt active MCP sessions and gather information useful for further attacks.

Patches

Fixed in v2.47.6. All MCP session endpoints now require Bearer authentication. The health check endpoint has been reduced to a minimal liveness response.

Workarounds

If you cannot upgrade immediately:

• Restrict network access to the HTTP server using firewall rules, reverse proxy IP allowlists, or a VPN so that only trusted clients can reach it.
• Use stdio mode (MCP_MODE=stdio) instead of HTTP mode. The stdio transport does not expose any HTTP endpoints and is unaffected by this vulnerability.

Upgrading to v2.47.6 is still strongly recommended.

Credit

Reported by @yotampe-pluto.