# vm2 NodeVM builtin allowlist bypass sandbox escape

Source: https://junglewise.ai/threats/duplicate-advisory-nodevm-builtin-allowlist-bypass-via-node-test-run-7e8a6e4e  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-17. Updated: 2026-10-01  
License: CC BY 4.0 with a link back

Severity: critical · CVSS 9.9 · Published 2026-09-17

vm2 is a JavaScript sandbox library that isolates untrusted code execution. When running on Node.js 24 and newer, attackers with code execution inside the sandbox can break out by exploiting a flaw in the builtin module allowlist, ultimately executing arbitrary JavaScript on the host system outside the sandbox.

Technologies: [vm2 (npm)](https://junglewise.ai/threats/technologies/vm2), [Patriksimek Vm2](https://junglewise.ai/threats/technologies/patriksimek-vm2). Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [Patriksimek](https://junglewise.ai/threats/vendors/patriksimek).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Critical severity, with a CVSS score of 9.9, published 17 September 2026.

**Which products and versions are affected?** vm2 (npm) >= 3.9.6, <= 3.11.6; Patriksimek Vm2 >=3.9.6, <=3.11.6.

**Is there a fix for This vulnerability?** A patch was published on 2026-08-24: Fixed in vm2 3.11.7 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked over the network.

**Am I affected?** Check whether you run vm2 (npm) or Patriksimek Vm2 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a chain of three issues: Node.js 24+ exposes a scheme-only builtin key "node:test" that bypasses vm2's family-based protection mechanism; the generic host-passthrough loader stores it when explicitly allowed; and requireImpl() in lib/setup-node-sandbox.js strips a single "node:" prefix, allowing sandbox code to call require('node:node:test') and obtain a proxy to the host module. Calling node:test.run() with attacker-controlled execArgv spawns an unrestricted host Node process that executes arbitrary code via --eval. Requires the embedder to explicitly allow node:test in the builtin allowlist and Node.js 24+.

## Affected products

- patriksimek vm2 >=3.9.6, <=3.11.6

## Timeline

- 2026-08-24: disclosed
- 2026-08-24: patched: Fixed in vm2 3.11.7

## References

- [https://github.com/patriksimek/vm2/security/advisories/GHSA-qhwx-74w5-xhxq](https://github.com/patriksimek/vm2/security/advisories/GHSA-qhwx-74w5-xhxq)

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- [vm2 NodeVM path bypass in custom resolution](https://junglewise.ai/threats/duplicate-advisory-vm2-nodevm-custom-resolution-bypasses-external-path-5d3a7272)
- [vm2 NodeVM zlib buffer pool information disclosure](https://junglewise.ai/threats/duplicate-advisory-vm2-nodevm-zlib-buffers-expose-pooled-host-memory-6007c734)
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