n8n: Authenticated XSS and Open Redirect via Form Node

Impact

An authenticated user with permission to create or modify workflows could configure a Form Node with an unsanitized HTML description field or exploit an overly permissive iframe sandbox policy to perform stored cross-site scripting or redirect end users visiting the form to an arbitrary external URL. The vulnerability could be used to facilitate phishing attacks.

Patches

The issue has been fixed in n8n versions 1.123.24, 2.10.4 and 2.12.0. Users should upgrade to one of these versions or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

• Limit workflow creation and editing permissions to fully trusted users only.
• Disable the Form node by adding n8n-nodes-base.form to the NODES_EXCLUDE environment variable.
• Disable the Form Trigger node by adding n8n-nodes-base.formTrigger to the NODES_EXCLUDE environment variable.

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