n8n Vulnerable to Denial of Service via Malformed Binary Data Requests

Summary

Denial of Service vulnerability in /rest/binary-data endpoint when processing empty filesystem URIs (filesystem:// or filesystem-v2://).

Impact

This is a Denial of Service (DoS) vulnerability that allows authenticated attackers to cause service unavailability through malformed filesystem URI requests. The vulnerability affects:

• The /rest/binary-data endpoint
• n8n.cloud instances (confirmed HTTP/2 524 timeout responses)

Attackers can exploit this by sending GET requests with empty filesystem URIs (filesystem:// or filesystem-v2://) to the /rest/binary-data endpoint, causing resource exhaustion and service disruption.

Patches

The issue has been patched in [1.99.0](https://github.com/n8n-io/n8n/releases/tag/n8n%401.99.0).

All users should upgrade to this version or later.

The fix introduces strict checking of URI patterns.

Patch commit: https://github.com/n8n-io/n8n/pull/16229