n8n: Authenticated XSS and Open Redirect via Form Node

Summary

## 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.