n8n: Reflected XSS via Facebook, WhatsApp, and Microsoft Teams Trigger Webhook Verification Endpoints

Impact

An endpoint in the Meta and Microsoft Teams trigger nodes reflects a query parameter into the HTTP response without sanitization or Content-Security-Policy headers, enabling reflected XSS in the n8n origin when a logged-in user visits a crafted URL.

Patches

The issue has been fixed in n8n version 2.24.0. Users should upgrade to this version or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Limit workflow creation and activation permissions to fully trusted users only. - Disable the affected nodes by adding n8n-nodes-base.facebookTrigger, n8n-nodes-base.whatsAppTrigger, n8n-nodes-base.facebookLeadAdsTrigger, and n8n-nodes-base.microsoftTeamsTrigger to the NODES_EXCLUDE environment variable.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.