GHSA-pr9r-gxgp-9rm8

## 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