n8n-mcp has unauthenticated session termination and information disclosure in HTTP transport
Date: 2026-04
Affected: npm/n8n-mcp
Attack vector: info-disclosure
Category: vulnerability-disclosure
Severity: High
CWE: CWE-306
CVSS: 8.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H)

### 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.


Mitigations:

Architectural layers (MAESTRO):