# vm2 NodeVM nesting guard bypass permits host RCE

Source: https://junglewise.ai/threats/duplicate-advisory-nodevm-nesting-guard-accepts-array-shaped-require-e4adbb8b  
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 · Published 2026-09-17

vm2 is a JavaScript sandbox that runs untrusted Node.js code in isolation. A logic flaw allows attackers to bypass the nesting guard by passing an array as the require option, enabling them to escape the sandbox and execute arbitrary commands with the privileges of the host Node.js process. This turns a sandbox protection mechanism into a complete security bypass with remote code execution.

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

## 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, published 17 September 2026.

**Which products and versions are affected?** vm2 (npm) >= 3.11.4, <= 3.11.6; Vm2 3.11.4 to 3.11.6.

**Is there a fix for This vulnerability?** A patch was published on 2026: 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, in a software library.

**Am I affected?** Check whether you run vm2 (npm) or 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 exists in the NodeVM constructor's type check for the requireOpts parameter, which uses `typeof requireOpts === 'object' && requireOpts !== null`. This check treats arrays as valid configuration objects, bypassing the intended guard that rejects nesting without explicit require configuration. When an array is passed, makeResolverFromLegacyOptions() destructures it to undefined fields and returns only NESTING_OVERRIDE.vm2, allowing an attacker to require the host vm2 module and create an inner NodeVM with an attacker-controlled builtin allowlist including child_process, enabling arbitrary command execution. The flaw affects vm2 versions 3.11.4 through 3.11.6 and is fixed in 3.11.7.

## Affected products

- vm2 3.11.4 to 3.11.6

## Timeline

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

## References

- [https://github.com/patriksimek/vm2/security/advisories/GHSA-8hr7-r645-pc6w](https://github.com/patriksimek/vm2/security/advisories/GHSA-8hr7-r645-pc6w)

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