CVE-2026-24118

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 __lookupGetter__ method allows to read the getter of an object. It is special in VM2 since it will switch between the host and sandbox version of the method when passed to the other context.
This allows to access getters on an object in the host context if the method is called from the host context which can be achieved by using the host apply method which can be accessed through Buffer.apply.
Afterwards, this function can be used to call the host version of __lookupGetter__ with Buffer and __proto__ resulting in the prototype lookup method from the host context.
With this method the hosts Function.prototype object can be retrieved and the host Function acquired through the constructor property which allows to create and run code in the host context.
This issue was attempted to be fixed with https://github.com/patriksimek/vm2/blob/4b009c2d4b1131c01810c1205e641d614c322a29/lib/bridge.js#L427. However, this can be circumvented by using Object.getOwnPropertyDescriptor to get the constructor property.

PoC

The following code demonstrates this issue by acquiring the host process object and executing touch pwned.

const {VM} = require("vm2");
const vm = new VM();
vm.run(`
const g = ({}).__lookupGetter__;
const a = Buffer.apply;
const p = a.apply(g, [Buffer, ['__proto__']]);
Object.getOwnPropertyDescriptor(p.call(a),'constructor').value('return process')().mainModule.require('child_process').execSync('touch pwned');
`);

Attackers can perform Remote Code Execution under the assumption that arbitrary code can be executed inside the context of a vm2 sandbox.

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-2026-24118 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 (3.11.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-24118? CVE-2026-24118 is a critical-severity code injection vulnerability in vm2 (npm), affecting versions <= 3.10.4. It is fixed in 3.11.0. Untrusted input is evaluated as executable code within the application's runtime environment.
2. How severe is CVE-2026-24118? CVE-2026-24118 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-2026-24118? vm2 (npm) versions <= 3.10.4 is affected.
4. Is there a fix for CVE-2026-24118? Yes. CVE-2026-24118 is fixed in 3.11.0. Upgrade to this version or later.
5. Is CVE-2026-24118 exploitable, and should I be worried? Whether CVE-2026-24118 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-2026-24118 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-2026-24118? Upgrade vm2 to 3.11.0 or later.