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?
- Critical severity, with a CVSS score of 9, published 17 September 2026.
- Which products and versions are affected?
- vm2 (npm) <= 3.11.7; Vm2 <= 3.11.7.
- Is there a fix for This vulnerability?
- Yes: fixed in 3.11.8. 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: 3.11.8
Technical details
vm2 3.11.7 and earlier fail to properly sanitize revisited host-wrapped AggregateError objects during exception handling. The handleException function uses a visited weakmap to detect cycles but returns the raw host proxy on revisit instead of the sanitized version; sanitizeAggregateError rebuilds errors into fresh LocalAggregateError objects but does not seal the original host carrier, allowing re-embedding of unsanitized host proxies. An attacker with the ability to throw a host AggregateError from an exposed host function can craft one with self-cycles or duplicate references to leak live host proxies and achieve RCE via child_process.execSync.
Affected products
- vm2 <= 3.11.7
Timeline
- 2026-08-27: disclosed
- 2026-09-17: advisory