n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service
Impact
An authenticated user able to create or edit a workflow expression could abuse the expression engine's array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process, leading to a denial of service.
Both self-hosted and cloud instances running the VM expression engine are affected.
Patches
The issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Restrict n8n instance access to fully trusted users only.
- Disable the VM expression engine if an alternative is available for your deployment.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | n8n | < 1.123.67, >= 2.32.0, < 2.32.1, >= 2.0.0-rc.0, < 2.31.5 | 1.123.67, 2.32.1, 2.31.5 |
References
- https://github.com/n8n-io/n8n/security/advisories/GHSA-hx4h-vr3m-45vh
- https://github.com/n8n-io/n8n/commit/f69dfc6dd2178a14ea1624d2e1d403c2e755042f
- https://github.com/n8n-io/n8n
- https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.67
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.31.5
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.32.1
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-1321- Platform
- npm
- Package
n8n- Disclosed
- 22.07.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-hx4h-vr3m-45vh - CC BY 4.0
Vulnerability history: n8n
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 156
- First → latest
- 05.2023 09.2026
- Without a fix
- 1
- Exploited in attacks
- 1
Severity breakdown
- Critical 24
- High 58
- Medium 74
Disclosures per year
- 2023: 3
- 2024: 0
- 2025: 14
- 2026: 139
-
n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service this entry
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