vm2: Sandboxed code can read and write host-realm memory via Node's shared Buffer pool

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:L

EPSS

• CVE-2026-92947: 0.48% estimated exploitation activity in the next 30 days; percentile 41.62 (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 Sandboxed code is able to disclose host memory used by small allocations by Buffer.from, Buffer.concat. Details vm2 exposes Buffer object to sandboxed code by default. Small Buffer allocations (for example, Buffer.allocUnsafe(), Buffer.from(array), Buffer.from(string), and Buffer.concat()) use the same Buffer pool, which is shared with the sandbox. This allows sandboxed code to disclose host memory used by the functions listed above. PoC Tested against vm2@3.11.5 in the node REPL. <img width="1044" height="104" alt="Screenshot 2026-07-23 at 17 54 15" src="https://github.com/user-attachments/assets/987b860c-6702-4818-bfaa-c77919c777e5" / Impact Since sandbox acquires an ArrayBuffer that is used by the host, it can disclose sensitive data going through functions mentioned above and even write to these buffers, which can lead to sensitive data exposure and potentially denial-of-service.

Published by the source

5 Oct 2026, 22:34 UTC

Last modified by the source

5 Oct 2026, 22:45 UTC

Source last checked

26 Oct 2026, 13:06 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-fcqc-726x-5wfc

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-fcqc-726x-5wfc

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-fcqc-726x-5wfc

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# Patch Next advisory brief: CVE-2026-92947

Advisory: vm2: Sandboxed code can read and write host-realm memory via Node's shared Buffer pool
IDs: CVE-2026-92947, GHSA-fcqc-726x-5wfc
Record: https://patchnext.com/advisories/cve-2026-92947 (revision 3, source checked 26 Oct 2026, 13:06 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 3.11.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm vm2: affected <= 3.11.6; fixed in 3.11.7

## 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-fcqc-726x-5wfc (GitHub-reviewed advisory GHSA-fcqc-726x-5wfc lists affected ranges: npm vm2 >=0 <=3.11.6)
- Verified: https://osv.dev/vulnerability/GHSA-fcqc-726x-5wfc (OSV record GHSA-fcqc-726x-5wfc lists affected ranges: npm vm2 >=0 <3.11.7 (fixed))

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