---
title: "CVE-2026-43997: vm2 Access to Host Object Enables Sandbox Escape"
url: https://erroneo.us/security/cve/CVE-2026-43997/
description: "CVE-2026-43997 (vm2 (npm)): vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, it is possible to obtain the host Object. There are various ways…"
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-2026-43997"
kev: false
cvss: 10
epss: 0.00767
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-43997: vm2 Access to Host Object Enables Sandbox Escape

**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 0.8% , percentile 55: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 55% 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) <= 3.10.5, fixed in 3.11.0 . Check your lockfile, including transitive dependencies.

## What it is

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, it is possible to obtain the host Object. There are various ways to use the host Object, to escape the sandbox, one example would be using HostObject.getOwnPropertySymbols to obtain Symbol(nodejs.util.inspect.custom). This vulnerability is fixed in 3.11.0.

## Affected packages

- npm `vm2` <= 3.10.5 → fixed: 3.11.0

## Affected products (CVE record)

- patriksimek vm2: < 3.11.0

## Severity

- GitHub_M CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
- redhat-SADP CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 10.0 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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): 0.77% probability of exploitation activity in the next 30 days; percentile 55.

## Sources

- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:50850)
- [GitHub Advisory GHSA-47x8-96vw-5wg6](https://github.com/advisories/GHSA-47x8-96vw-5wg6)
- [CVE.org record CVE-2026-43997](https://www.cve.org/CVERecord?id=CVE-2026-43997)
- [NVD entry CVE-2026-43997](https://nvd.nist.gov/vuln/detail/CVE-2026-43997)
- [github.com](https://github.com/patriksimek/vm2/security/advisories/GHSA-47x8-96vw-5wg6)
- [access.redhat.com](https://access.redhat.com/security/cve/CVE-2026-43997)
- [RHBZ#2477203](https://bugzilla.redhat.com/show_bug.cgi?id=2477203)
- [security.access.redhat.com](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43997.json)
- [github.com](https://github.com/patriksimek/vm2/releases/tag/v3.11.0)

---
Source page: https://erroneo.us/security/cve/CVE-2026-43997/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt