Executive brief
n8n-mcp is a node.js library that provides Model Context Protocol (MCP) transport capabilities over HTTP and other protocols. Without proper authentication, an attacker can terminate active MCP sessions and extract sensitive operational metadata from the health check endpoint, disrupting service operations and gathering intelligence for further attacks.
Technical details
The vulnerability stems from missing authentication (CWE-306) on several HTTP transport endpoints, particularly GET /mcp and DELETE /mcp routes, which relied on inconsistent secondary validation rather than explicit Bearer token authentication. The health check endpoint (GET /health) also exposed sensitive operational metadata including session statistics, memory usage, environment details, and token metadata without requiring credentials. An unauthenticated attacker with network access to the HTTP server can exploit this to terminate active MCP sessions via DELETE /mcp or gather operational information via GET /health. The fix, deployed in v2.47.6, adds mandatory Bearer authentication to all MCP session endpoints and trims the health endpoint to a minimal liveness response containing only status, version, uptime, and timestamp.
Affected products
- n8n n8n-mcp < 2.47.6
Timeline
- 2026-04-10: disclosed
- 2026-04-10: patched: Fixed in v2.47.6