vm2 is Vulnerable to Sandbox Breakout Through Promise Species

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-47208: 1.04% estimated exploitation activity in the next 30 days; percentile 64.01 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 The localPromise constructor was changed to call this.then(undefined, eater) to ensure a rejected promise is always used. However, this is missing a call to resetPromiseSpecies to ensure that this has no special species. Since the species can be changed a custom promise can be used to supply a custom reject method to the executor allowing to get a raw host error and escape the sandbox. PoC Impact Attackers can perform Remote Code Execution under the assumption that the attacker can run arbitrary code execution inside the context of a vm2 sandbox.

Published by the source

29 May 2026, 17:40 UTC

Last modified by the source

12 Jun 2026, 21:00 UTC

Source last checked

26 Oct 2026, 12:55 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-76w7-j9cq-rx2j

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-76w7-j9cq-rx2j

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-76w7-j9cq-rx2j

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# Patch Next advisory brief: CVE-2026-47208

Advisory: vm2 is Vulnerable to Sandbox Breakout Through Promise Species
IDs: CVE-2026-47208, GHSA-76w7-j9cq-rx2j
Record: https://patchnext.com/advisories/cve-2026-47208 (revision 3, source checked 26 Oct 2026, 12:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 10.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: vm2 3.11.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm vm2: affected <= 3.11.3; fixed in 3.11.4

## Suggested inspection (read-only)
- `npm ls vm2 --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on vm2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-76w7-j9cq-rx2j (GitHub-reviewed advisory GHSA-76w7-j9cq-rx2j lists affected ranges: npm vm2 >=0 <=3.11.3)
- Verified: https://osv.dev/vulnerability/GHSA-76w7-j9cq-rx2j (OSV record GHSA-76w7-j9cq-rx2j lists affected ranges: npm vm2 >=0 <3.11.4 (fixed))

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