Description
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as __proto__ to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| n8n-io | n8n | < 2.41.4, 2.42.0 – < 2.42.1 | 2.41.4 |
Advisories 1
- WID-SEC-2026-3898 n8n: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 28, 2026
References
- GitHub Security Advisory (GHSA-fvv4-gmv9-xqf5) vendor-advisory
- VulnCheck Advisory: n8n before 2.41.4 and 2.42.1 Prototype Pollution DoS via Workflow History Compaction third-party-advisory