---
title: "CVE-2026-44008: vm2 has sandbox breakout via `neutralizeArraySpeciesBatch`"
url: https://erroneo.us/security/cve/CVE-2026-44008/
description: "CVE-2026-44008 (vm2 (npm)): vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.2, the new method neutralizeArraySpeciesBatch works with objects…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-13
date_modified: 2026-09-07
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-44008"
kev: false
cvss: 9.8
epss: 0.00901
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-44008: vm2 has sandbox breakout via `neutralizeArraySpeciesBatch`

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.9% , percentile 59: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 59% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes vm2 (npm) <= 3.11.1, fixed in 3.11.2 . Check your lockfile, including transitive dependencies.

## What it is

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.2, the new method neutralizeArraySpeciesBatch works with objects from the other side but can call into this side via getter on the array prototype exposing objects of the wrong side into the sandbox. This can be used to get host objects and get the host Function object. This allows attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system. This vulnerability is fixed in 3.11.2.

## Affected packages

- npm `vm2` <= 3.11.1 → fixed: 3.11.2

## Affected products (CVE record)

- patriksimek vm2: < 3.11.2

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- redhat-SADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.90% probability of exploitation activity in the next 30 days; percentile 59.

## Sources

- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:50850)
- [GitHub Advisory GHSA-9qj6-qjgg-37qq](https://github.com/advisories/GHSA-9qj6-qjgg-37qq)
- [CVE.org record CVE-2026-44008](https://www.cve.org/CVERecord?id=CVE-2026-44008)
- [NVD entry CVE-2026-44008](https://nvd.nist.gov/vuln/detail/CVE-2026-44008)
- [github.com](https://github.com/patriksimek/vm2/security/advisories/GHSA-9qj6-qjgg-37qq)
- [access.redhat.com](https://access.redhat.com/security/cve/CVE-2026-44008)
- [RHBZ#2477201](https://bugzilla.redhat.com/show_bug.cgi?id=2477201)
- [security.access.redhat.com](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44008.json)
- [github.com](https://github.com/patriksimek/vm2/releases/tag/v3.11.2)

---
Source page: https://erroneo.us/security/cve/CVE-2026-44008/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt