| Package | Affected versions | Patched versions |
|---|---|---|
| n8n-mcp | ≥ 2.18.7, < 2.50.2 | 2.50.2 |
| n8n-mcp | ≥ 2.18.7, < 2.50.2 | 2.50.2 |
Authenticated Server-Side Request Forgery affecting the webhook trigger tools, the n8n API client (N8N_API_URL), and per-request URLs supplied via the x-n8n-url header in multi-tenant HTTP mode.
A caller with access to the MCP session can drive HTTP requests from the n8n-mcp host to internal services and cloud metadata endpoints that the SSRF gate is meant to block. The response body is returned to the caller, making internal-service enumeration and credential theft immediate without any out-of-band channel.
AUTH_TOKEN: any tenant with valid credentials can reach the operator's cloud metadata service and exfiltrate temporary IAM / GCP service account / Azure managed-identity credentials.Fixed in [email protected].
Note for operators: The same SSRF gate that previously covered webhook URLs now also covers the n8n API client base URL. If N8N_API_URL points at http://localhost:5678 (n8n on the same host) or an RFC1918 address (n8n on the same private network), set WEBHOOK_SECURITY_MODE=moderate (allows localhost, still blocks RFC1918 and cloud metadata) or WEBHOOK_SECURITY_MODE=permissive (allows RFC1918 too — only safe on a trusted private network). Default strict is correct for deployments where n8n is reachable at a public hostname.
For deployments that cannot upgrade immediately:
169.254.169.254, 169.254.170.2, 100.100.100.200, 192.0.0.192, and the GCP metadata.google.internal resolved IP) and any RFC1918 networks the server does not legitimately need to reach.AUTH_TOKEN to compromise).DISABLED_TOOLS=n8n_trigger_webhook_workflow,n8n_create_workflow,n8n_test_workflow if the deployment does not need them.Running one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site freeReported by @fg0x0.