Executive brief
n8n is a workflow automation platform that allows users to create and execute complex business processes. A flaw in its XML webhook parser allows authenticated users with workflow creation permissions to inject malicious XML that corrupts JavaScript object prototypes. By chaining this exploit with n8n's Git node (which supports SSH operations), an attacker can execute arbitrary code on the n8n server, enabling full system compromise.
Technical details
The vulnerability is a prototype pollution flaw (CWE-1321) in the xml2js library used by n8n's webhook handler to parse XML request bodies. A crafted XML payload can pollute the JavaScript object prototype, allowing an authenticated user to modify object behavior globally. The attack requires the attacker to have permission to create or modify workflows (low privilege requirement). By chaining the prototype pollution with Git node SSH operations, an attacker achieves remote code execution on the host. Patches are available in n8n versions 1.123.32, 2.17.4, and 2.18.1.
Affected products
- n8n n8n < 1.123.32, 2.17.0-2.17.3, 2.18.0
Timeline
- 2026-04-29: disclosed: Advisory published
- 2026-04-22: patched: Fixes available in versions 1.123.32, 2.17.4, and 2.18.1