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Luu, T.J.

GHSA-8g7g-hmwm-6rv2: n8n-mcp affected by path traversal, redirect-following SSRF, and telemetry payload exposure

highvulnerability

security

Source: GitHub Advisory DatabaseMay 8, 2026

Summary

n8n-mcp versions before 2.50.1 had three security issues: unvalidated workflow IDs allowed attackers to bypass access controls and leak API keys, webhook URLs followed redirects to unintended hosts (SSRF, a type of attack where a server makes unwanted requests to other systems), and telemetry (usage data sent to developers) stored sensitive information like API keys without hiding it. The vulnerability has a CVSS score (a 0-10 rating of how severe a vulnerability is) of 8.3 and requires an authenticated attacker with access to the n8n API.

Solution / Mitigation

Upgrade to n8n-mcp version 2.50.1 or later. If upgrading is not immediately possible, the source provides these workarounds: for issues 1 and 2, restrict network access to the HTTP port through firewall rules or switch to stdio mode (a communication method that does not expose HTTP); for issue 3, set the environment variable `N8N_MCP_TELEMETRY_DISABLED=true` before starting the server, or run `npx n8n-mcp telemetry disable` once.