Quick answers
- Is This vulnerability exploited in the wild?
- No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
- How severe is This vulnerability?
- Medium severity, with a CVSS score of 6.8, published 27 September 2026.
- Which products and versions are affected?
- vm2 (npm) < 3.12.2; Vm2 < 3.12.2.
- Is there a fix for This vulnerability?
- Yes: fixed in 3.12.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is This vulnerability attacked?
- It is attacked over the network, in a software library.
- Am I affected?
- Check whether you run vm2 (npm) or Vm2 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
- Fixed in: 3.12.2
Technical details
The vulnerability exists in BaseHandler.construct, which does not apply the same host-side Promise rejection handling (markHostPromiseHandled) that BaseHandler.apply already performs. When an embedder exposes a constructable host function whose constructor returns a native rejected Promise, an untrusted script can invoke it with the `new` operator and ignore the result, allowing the unhandled rejection to cross the sandbox boundary and crash the Node.js host process under strict unhandled-rejection policy.
Affected products
- vm2 < 3.12.2
Timeline
- 2026-09-08: disclosed
- 2026-09-27: patched