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?
- High severity, with a CVSS score of 7.5, published 17 September 2026.
- Which products and versions are affected?
- vm2 (npm) <= 3.11.6; Vm2 <= 3.11.6.
- Is there a fix for This vulnerability?
- Yes: fixed in 3.11.7. 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: 3.11.7
Technical details
The vulnerability exists because vm2's timeout enforcement wraps only the synchronous VM#run() call but not asynchronous callbacks triggered by the V8 garbage collector. FinalizationRegistry and WeakRef are exposed unmodified to sandboxed code and not hardened, allowing an attacker to register a cleanup callback that executes outside any timeout protection when an object is garbage collected. A malicious cleanup callback can then execute a busy loop, causing denial of service by blocking the host event loop indefinitely.
Affected products
- vm2 <= 3.11.6
Timeline
- 2026-08-24: disclosed
- 2026-09-17: advisory
- 2026-10-05: other: Advisory withdrawn as duplicate of GHSA-r4fx-v8hh-22mv