# vm2 Promise rejection denial of service

Source: https://junglewise.ai/threats/duplicate-advisory-vm2-host-returned-promise-rejection-can-bypass-vm2-s-e131e247  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-17. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

Severity: high · CVSS 8.6 · Published 2026-09-17

vm2 is a JavaScript sandbox library that lets applications safely run untrusted code in Node.js. A vulnerability allows sandboxed code to crash the host process by ignoring a Promise returned from host code, bypassing vm2's protections against unhandled promise rejections. This affects any application using vm2 to execute untrusted scripts, potentially enabling denial-of-service attacks.

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?** High severity, with a CVSS score of 8.6, published 17 September 2026.

**Which products and versions are affected?** vm2 (npm) >= 3.10.0, <= 3.11.7; Patriksimek Vm2 3.10.0 through 3.11.7.

**Is there a fix for This vulnerability?** Yes: fixed in 3.11.8. 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.

## How to fix

- Fixed in 3.11.8

## Technical details

Promises returned from the host realm into the sandbox are not marked as handled at the bridge boundary (versions 3.10.0–3.11.7). Sandboxed code can call a host function returning a rejected Promise and ignore the return value, leaving the host Promise unhandled so Node.js terminates the process. This is an incomplete fix of the prior unhandled-rejection hardening (GHSA-hw58-p9xv-2mjh), where only sandbox-created Promises were wrapped with rejection handlers, not host-returned Promises.

## Affected products

- patriksimek vm2 3.10.0 through 3.11.7

## Timeline

- 2026-08-27: disclosed
- 2026-08-27: patched: Advisory GHSA-gjq8-xm47-88rc published
- 2026-09-17: advisory: Duplicate advisory GHSA-mgj2-jqjq-q8gg published
- 2026-10-05: other: Duplicate advisory withdrawn

## References

- [https://github.com/patriksimek/vm2/security/advisories/GHSA-gjq8-xm47-88rc](https://github.com/patriksimek/vm2/security/advisories/GHSA-gjq8-xm47-88rc)

## Related threats

- [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)
- [vm2 host Promise rejection denial of service in construct trap](https://junglewise.ai/threats/duplicate-advisory-vm2-host-promise-rejection-from-an-exposed-f7aba6ba)
- [vm2 sandbox escape via Buffer backing-store ownership bypass](https://junglewise.ai/threats/cve-2026-100723-vm2-before-3-12-2-does-not-apply-its-buffer-backing-store)
- [vm2 unhandled Promise rejection in construct trap](https://junglewise.ai/threats/cve-2026-100722-vm2-before-3-12-2-does-not-apply-host-side-promise-rejection)