# CVE-2026-92958: vm2 builtin denylist bypass in NodeVM

Source: https://junglewise.ai/threats/cve-2026-92958-vm2-builtin-denylist-bypass-in-nodevm  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-17. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-92958 · Severity: high · CVSS 8.5 · Published 2026-09-17

vm2 is a JavaScript sandbox engine used to safely run untrusted code in an isolated environment. This vulnerability allows sandboxed code to bypass filesystem access restrictions and directly access fs/promises, enabling attackers to create and modify files on the host system despite the embedder explicitly denying fs access. Organizations using vm2 to sandbox user-submitted code or plugins face direct data exposure and system compromise risks.

Technologies: [vm2 (npm)](https://junglewise.ai/threats/technologies/vm2). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-92958 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-92958 being exploited in the wild.

**How severe is CVE-2026-92958?** High severity, with a CVSS score of 8.5, published 17 September 2026.

**Which products and versions are affected?** vm2 (npm) <= 3.11.6, SEMVER:introduced=0,fixed=3.11.7.

**Is there a fix for CVE-2026-92958?** Yes. vm2 (npm): upgrade to 3.11.7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-92958 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-92958?** Check whether you run vm2 (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- vm2 (npm): upgrade to 3.11.7 or later

  ```sh
  npm install vm2@3.11.7
  ```


## Technical details

The vulnerability is a denylist bypass in NodeVM's builtin module filtering (lib/builtin.js). When using a wildcard policy (e.g., require: { builtin: ['*', '-fs', '-child_process'] }), negative entries are matched by exact module name only. This means -fs blocks only the fs module itself but not fs/promises or node:fs/promises. Additionally, the node: prefix handling is inconsistent—negative entries like -node:fs/promises do not block require('fs/promises'). An attacker with code execution in the sandbox can call require('fs/promises') to access the promise-based filesystem API, then use methods like fsp.writeFile(), mkdir, rm, and others to read/write/modify files on the host. The attack requires no additional privileges or user interaction. This issue is fixed in vm2 3.11.7.

## Affected products

- vm2 vm2 through 3.11.6

## Identifiers

- CVE-2026-92958
- GHSA-6rh5-qq4q-97xh

## Timeline

- 2026-08-24: disclosed: GitHub Security Advisory GHSA-6rh5-qq4q-97xh published
- 2026-09-17: advisory: CVE-2026-92958 published
- 2026: patched: Fixed in vm2 3.11.7

## References

- [https://github.com/patriksimek/vm2/security/advisories/GHSA-6rh5-qq4q-97xh](https://github.com/patriksimek/vm2/security/advisories/GHSA-6rh5-qq4q-97xh)
- [https://www.vulncheck.com/advisories/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)

## Related threats

- [vm2 NodeVM path bypass in custom resolution](https://junglewise.ai/threats/duplicate-advisory-vm2-nodevm-custom-resolution-bypasses-external-path-5d3a7272)
- [vm2 NodeVM zlib buffer pool information disclosure](https://junglewise.ai/threats/duplicate-advisory-vm2-nodevm-zlib-buffers-expose-pooled-host-memory-6007c734)
- [vm2 host Promise rejection denial of service in construct trap](https://junglewise.ai/threats/duplicate-advisory-vm2-host-promise-rejection-from-an-exposed-f7aba6ba)
- [vm2 sandbox escape via Buffer backing-store ownership bypass](https://junglewise.ai/threats/cve-2026-100723-vm2-before-3-12-2-does-not-apply-its-buffer-backing-store)
- [vm2 unhandled Promise rejection in construct trap](https://junglewise.ai/threats/cve-2026-100722-vm2-before-3-12-2-does-not-apply-host-side-promise-rejection)