---
title: "CVE-2026-92958: vm2 before 3.11.7 Denylist Bypass via fs/promises"
url: https://erroneo.us/security/cve/CVE-2026-92958/
description: "CVE-2026-92958 (patriksimek vm2): vm2 through 3.11.6 contains a builtin-module denylist bypass in NodeVM. When the embedder uses the builtin wildcard…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-17
date_modified: 2026-10-07
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-92958"
kev: false
cvss: 8.4
epss: 0.00384
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-92958: vm2 before 3.11.7 Denylist Bypass via fs/promises

**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 0.4% , percentile 31: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 31% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- 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 through 3.11.6 contains a builtin-module denylist bypass in NodeVM. When the embedder uses the builtin wildcard together with negative entries (e.g. require: { builtin: ['', '-fs', '-childprocess'] }), negative entries are matched by exact module name in lib/builtin.js, so -fs removes only the builtin named fs and does not remove builtin subpaths such as fs/promises. Sandboxed code can therefore call require('fs/promises') or require('node:fs/promises') and reach the promise-based filesystem API despite fs being denied; node: prefix handling is likewise inconsistent (a -node:fs/promises entry does not block require('fs/promises')). Host file creation and writing were confirmed via fsp.writeFile(), and other fs/promises operations (cp, mkdir, rename, rm, rmdir, truncate, read operations, etc.) are also reachable. This issue is fixed in vm2 3.11.7.

## Affected products (CVE record)

- patriksimek vm2: < 3.11.7

## Severity

- VulnCheck CVSS 4.0: 8.4 `CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L`
- VulnCheck CVSS 3.1: 8.5 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L`

## 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): 0.38% probability of exploitation activity in the next 30 days; percentile 31.

## Sources

- [GitHub Security Advisory (GHSA-6rh5-qq4q-97xh)](https://github.com/patriksimek/vm2/security/advisories/GHSA-6rh5-qq4q-97xh)
- [CVE.org record CVE-2026-92958](https://www.cve.org/CVERecord?id=CVE-2026-92958)
- [NVD entry CVE-2026-92958](https://nvd.nist.gov/vuln/detail/CVE-2026-92958)
- [VulnCheck Advisory: vm2 before 3.11.7 Denylist Bypass via fs/promises](https://www.vulncheck.com/advisories/vm2-before-3.11.7-denylist-bypass-via-fs-promises)

---
Source page: https://erroneo.us/security/cve/CVE-2026-92958/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt