AI agent vulnerability · n8n

GHSA-hx4h-vr3m-45vh: n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service

mediumCVSS 4.0 6.1

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.

Published Jul 22, 2026

Affected packages

n8n

Ecosystem: npm
Affected: < 1.123.67
Fixed in: 1.123.67
Check: npm ls n8n

n8n

Ecosystem: npm
Affected: >= 2.32.0, < 2.32.1
Fixed in: 2.32.1
Check: npm ls n8n

n8n

Ecosystem: npm
Affected: >= 2.0.0-rc.0, < 2.31.5
Fixed in: 2.31.5
Check: npm ls n8n

Advisory details

From the GitHub Advisory Database (CC BY 4.0).

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.

Credited to zolbooo.

References

How this page is made: the data panel comes from the GitHub Advisory Database, CISA’s KEV catalog, the NVD and FIRST EPSS, and updates twice a day. No analysis has been written for this entry yet. Methodology

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