Summary
n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service
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.
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.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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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.
Frequently Asked Questions
- What is GHSA-HX4H-VR3M-45VH? GHSA-HX4H-VR3M-45VH is a medium-severity security vulnerability in n8n (npm), affecting versions < 1.123.67. It is fixed in 1.123.67, 2.32.1, 2.31.5.
- Which versions of n8n are affected by GHSA-HX4H-VR3M-45VH? n8n (npm) versions < 1.123.67 is affected.
- Is there a fix for GHSA-HX4H-VR3M-45VH? Yes. GHSA-HX4H-VR3M-45VH is fixed in 1.123.67, 2.32.1, 2.31.5. Upgrade to this version or later.
- Is GHSA-HX4H-VR3M-45VH exploitable, and should I be worried? Whether GHSA-HX4H-VR3M-45VH is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-HX4H-VR3M-45VH is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-HX4H-VR3M-45VH?
- Upgrade
n8nto 1.123.67 or later - Upgrade
n8nto 2.32.1 or later - Upgrade
n8nto 2.31.5 or later
- Upgrade