CVE-2026-92954: vm2 host Promise rejection denial of service

CVE-2026-92954 · Severity: high · CVSS 8.6 · Published 2026-09-17

vm2 is a sandbox library that isolates untrusted JavaScript code running in Node.js. Attackers who execute code within the sandbox can trigger a denial of service by calling host functions that return rejected Promises and ignoring the result, causing the entire host process to terminate. In multi-tenant or service environments, this allows a small malicious script to crash the worker, disrupting service availability.

Technologies: vm2 (npm). Vendors: npm.

Quick answers

Is CVE-2026-92954 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-92954 being exploited in the wild.
How severe is CVE-2026-92954?
High severity, with a CVSS score of 8.6, published 17 September 2026.
Which products and versions are affected?
vm2 (npm) >= 3.10.0, <= 3.11.7, SEMVER:introduced=3.10.0,fixed=3.11.8.
Is there a fix for CVE-2026-92954?
Yes. vm2 (npm): upgrade to 3.11.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-92954 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-92954?
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 3.11.8 or later
    npm install vm2@3.11.8

Technical details

The vulnerability is a Promise rejection handling bypass in vm2's sandbox bridge. When untrusted code calls a host function that returns a rejected Promise (such as events.once() or any embedder-exposed Promise-returning API) and does not attach a .catch() or .then() handler, the host-side Promise remains unhandled. While vm2 wraps sandbox-created Promises with rejection handlers, host Promises are only instrumented when sandbox code explicitly calls .then/.catch/.finally on them. If the Promise is ignored, Node.js's default unhandled-rejection behavior (process termination) occurs, crashing the host. This affects versions 3.10.0 through 3.11.7; the fix in 3.11.8 adds host-side rejection handlers at the bridge boundary for all returned Promises.

Affected products

  • patriksimek vm2 3.10.0 through 3.11.7

Identifiers

  • CVE-2026-92954
  • GHSA-gjq8-xm47-88rc

Timeline

  • 2026-08-27: disclosed
  • 2026-09-17: advisory
  • 2026-09-17: patched: Fixed in version 3.11.8

References

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