---
id: GHSA-9538-79j2-h62h
title: >-
  Duplicate Advisory: `allowAsync: false` can be bypassed through Promise
  thenable assimilation in VM and NodeVM
summary: >-
  Duplicate Advisory: `allowAsync: false` can be bypassed through Promise
  thenable assimilation in VM and NodeVM
severity: high
cvss: 7.1
cwe:
  - CWE-693
vendor: vm2
product: vm2
ecosystem: npm
affected:
  - vm2 <= 3.11.7
published: '2026-09-17'
updated: '2026-10-05'
sourceUpdated: '2026-10-05T22:47:22Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-9538-79j2-h62h'
references:
  - url: 'https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-92959'
  - url: >-
      https://www.vulncheck.com/advisories/vm2-before-3.11.8-allowasync-bypass-via-promise-thenable
  - url: 'https://github.com/advisories/GHSA-9538-79j2-h62h'
tags:
  - ghsa
  - npm
ingestedAt: '2026-10-05T23:36:21.177Z'
---

## Overview

## Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-f8gf-w286-fmq2. This link is maintained to preserve external references.

## Original Description
vm2 before 3.11.8 does not fully enforce the allowAsync: false option in VM and NodeVM. While localPromise.prototype.then is replaced with a handler that throws 'Async not available', the sandbox's Promise static methods (Promise.resolve, Promise.all, Promise.race, Promise.any, and Promise.allSettled) still assimilate attacker-supplied thenables: native promise resolution performs PromiseResolveThenableJob and invokes the sandboxed code's then method in a microtask without passing through the patched then, so the async restriction is never applied. As a result, sandboxed script can schedule work that runs after VM.run() or NodeVM.run() has returned and outside the configured timeout, continuing to execute after the host believes execution is complete.

## Affected packages

- `vm2 <= 3.11.7`

## Remediation

Refer to the advisory for the patched release.