Vulnerability Description
vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, a sandbox boundary violation in vm2 allows host object identity to cross into the sandbox through host Promise resolution. When a host-side Promise that resolves to a host object is exposed to the sandbox, the value delivered to the sandbox .then() callback preserves host identity. This allows the sandbox to interact with the host object directly, including performing identity checks using host-side WeakMap and mutating host object state from inside the sandbox. This behavior occurs because the Promise fulfillment wrapper uses ensureThis() instead of the stronger cross-realm conversion path (from() / proxy wrapping). If no prototype mapping is found, ensureThis() returns the original object. As a result, objects resolved by host Promises can cross the sandbox boundary without proper isolation. This vulnerability is fixed in 3.11.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Vm2 Project | Vm2 | < 3.11.0 |
Related Weaknesses (CWE)
References
- https://github.com/patriksimek/vm2/security/advisories/GHSA-mpf8-4hx2-7cjgExploitVendor Advisory
- https://github.com/patriksimek/vm2/security/advisories/GHSA-mpf8-4hx2-7cjgExploitVendor Advisory
FAQ
What is CVE-2026-44000?
CVE-2026-44000 is a vulnerability with a CVSS score of 6.5 (MEDIUM). vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, a sandbox boundary violation in vm2 allows host object identity to cross into the sandbox through host Promise resolution. When a host-si...
How severe is CVE-2026-44000?
CVE-2026-44000 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-44000?
Check the references section above for vendor advisories and patch information. Affected products include: Vm2 Project Vm2.