n8n allows open redirects via the /signin endpoint

Impact

This is an Open Redirect (CWE-601) vulnerability in the login flow of n8n. Authenticated users can be redirected to untrusted, attacker-controlled domains after logging in, by crafting malicious URLs with a misleading redirect query parameter.

This may lead to:

• Phishing attacks by impersonating the n8n UI on lookalike domains (e.g., n8n.local.evil.com)
• Credential or 2FA theft if users are tricked into re-entering sensitive information
• Reputation risk due to the visual similarity between attacker-controlled domains and trusted ones

The vulnerability affects anyone hosting n8n and exposing the /signin endpoint to users.

Patches

The issue has been patched in [1.98.0](https://github.com/n8n-io/n8n/releases/tag/n8n%401.98.0).

All users should upgrade to this version or later.

The fix introduces strict origin validation for redirect URLs, ensuring only same-origin or relative paths are allowed after login.

Patch commit: https://github.com/n8n-io/n8n/pull/16034