n8n before 1.123.67, 2.31.5, and 2.32.1 contains a prototype pollution vulnerability in the VM expression engine. An authenticated user able to create or edit a workflow expression can abuse the engine's array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process (a sandbox escape), leading to a denial of service. Both self-hosted and cloud instances running the VM expression engine are affected.
CVE-2026-72769
CVSS base score
8.1 (v3.1)
Severity
HIGH
Attack vector
Network
Weakness
CWE-1321
Last modified
October 29, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Affected products
n8n n8n
References
- github.com Mitigation, Vendor Advisory
- www.vulncheck.com Third Party Advisory