---
title: "CVE-2026-47210: vm2 sandbox escape via JSPI-backed Promise `.finally()` species bypass"
url: https://erroneo.us/security/cve/CVE-2026-47210/
description: "CVE-2026-47210 (vm2 (npm)): vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, a sandbox escape vulnerability in vm2 allows arbitrary…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-06-12
date_modified: 2026-06-13
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-47210"
kev: false
cvss: 9.8
epss: 0.00823
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-47210: vm2 sandbox escape via JSPI-backed Promise `.finally()` species bypass

**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 57: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 57% 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) <= 3.11.3, fixed in 3.11.4 . Check your lockfile, including transitive dependencies.

## What it is

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, a sandbox escape vulnerability in vm2 allows arbitrary code execution in the host process when untrusted code is executed with async support on runtimes exposing WebAssembly JSPI (WebAssembly.promising / WebAssembly.Suspending). In the tested configuration, a JSPI-backed Promise can reach Promise.prototype.finally() in a way that bypasses the expected Promise-species hardening and exposes a host-originated rejection object to attacker-controlled species logic, breaking the sandbox boundary. This issue has been patched in version 3.11.4.

## Affected packages

- npm `vm2` <= 3.11.3 → fixed: 3.11.4

## Affected products (CVE record)

- patriksimek vm2: < 3.11.4

## 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`
- 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): 0.82% probability of exploitation activity in the next 30 days; percentile 57.

## Sources

- [GitHub Advisory GHSA-6j2x-vhqr-qr7q](https://github.com/advisories/GHSA-6j2x-vhqr-qr7q)
- [CVE.org record CVE-2026-47210](https://www.cve.org/CVERecord?id=CVE-2026-47210)
- [NVD entry CVE-2026-47210](https://nvd.nist.gov/vuln/detail/CVE-2026-47210)
- [github.com](https://github.com/patriksimek/vm2/security/advisories/GHSA-6j2x-vhqr-qr7q)
- [github.com](https://github.com/patriksimek/vm2/commit/6915fa4d9bcebd47b9a4f39a1adc1aa94ef6ffc6)
- [github.com](https://github.com/patriksimek/vm2/releases/tag/v3.11.4)

---
Source page: https://erroneo.us/security/cve/CVE-2026-47210/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt