Description
n8n versions before 2.34.1 contain a credential validation bypass in the MCP create_workflow_from_code tool when authentication type is set to an expression. Attackers with a valid MCP Bearer API key and knowledge of a target credential ID can persist unauthorized cross-project credential references on workflows in different projects.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| n8n-io | n8n | 2.34.0 – < 2.34.1, 2.0.0 – < 2.33.4 | 2.34.1 |
Advisories 1
- WID-SEC-2026-2681 n8n: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 20, 2026
References
- GitHub Security Advisory (GHSA-vfrj-582q-mvcp) vendor-advisory
- VulnCheck Advisory: n8n before 2.34.1 Cross-Project Credential Access via MCP third-party-advisory