---
title: "CVE-2026-100722: vm2 before 3.12.2 Host Process Termination via Construct Trap"
url: https://erroneo.us/security/cve/CVE-2026-100722/
description: "CVE-2026-100722 (patriksimek vm2): vm2 before 3.12.2 does not apply host-side Promise rejection handling in the sandbox-to-host construct trap. In…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-27
date_modified: 2026-10-07
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-100722"
kev: false
cvss: 8.9
epss: 0.0026
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-100722: vm2 before 3.12.2 Host Process Termination via Construct Trap

**Signal:** Normal patch cycle. No exploitation signal; fix it in your next routine update if you are affected. (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 0.3% , percentile 17: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 17% of all scored CVEs (low). 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.
- Editorial verdict: Check exposure. vm2: 22 Critical Sandbox Escapes, Fixed in 3.12.2 — If anything outside your trust boundary can get code into vm2, upgrade to 3.12.2 today and plan to move that code out of process; if vm2 only runs your own code, upgrade on a normal cycle.

## What it is

vm2 before 3.12.2 does not apply host-side Promise rejection handling in the sandbox-to-host construct trap. In BaseHandler, the apply trap calls markHostPromiseHandled() on the returned value, but the adjacent construct path returns the result of Reflect.construct without the same sanitization. If an embedder exposes a constructable host function whose constructor returns a native rejected Promise, an untrusted script executed via VM.run can invoke it with new and ignore the result; the rejected host Promise crosses the bridge unhandled and, under Node's strict unhandled-rejection policy, is promoted to an uncaught exception that terminates the host process.

## Affected products (CVE record)

- patriksimek vm2: < 3.12.2

## Severity

- VulnCheck CVSS 4.0: 8.9 `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H`
- VulnCheck CVSS 3.1: 6.8 `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.26% probability of exploitation activity in the next 30 days; percentile 17.

## Sources

- [GitHub Security Advisory (GHSA-2v2p-6j97-cjg9)](https://github.com/patriksimek/vm2/security/advisories/GHSA-2v2p-6j97-cjg9)
- [CVE.org record CVE-2026-100722](https://www.cve.org/CVERecord?id=CVE-2026-100722)
- [NVD entry CVE-2026-100722](https://nvd.nist.gov/vuln/detail/CVE-2026-100722)
- [VulnCheck Advisory: vm2 before 3.12.2 Host Process Termination via Construct Trap](https://www.vulncheck.com/advisories/vm2-before-3.12.2-host-process-termination-via-construct-trap)

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Source page: https://erroneo.us/security/cve/CVE-2026-100722/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt