vm2: Host Promise rejection from an exposed constructor can terminate the vm2 host process

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

vm2 before 3.12.2 does not apply host-side Promise rejection handling in the sandbox-to-host construct trap. In BaseHandler, the apply trap calls markHostPromiseHandled() on the returned value, but the adjacent construct path returns the result of Reflect.construct without the same sanitization. If an embedder exposes a constructable host function whose constructor returns a native rejected Promise, an untrusted script executed via VM.run can invoke it with `new` and ignore the result; the rejected host Promise crosses the bridge unhandled and, under Node's strict unhandled-rejection policy, is promoted to an uncaught exception that terminates the host process.

[ Fixes ]Fixes and patches

• vm2 3.12.2Fixed version · GitHub Advisories · npm package vm2: upgrade to 3.12.2 or later (affected <= 3.12.1)

[ Advisories ]Government CERT advisories

• BSI CERT-Bund27 Sep 2026WID-SEC-2026-3594

  vm2: Multiple vulnerabilities Translated from German

  CVE-2026-100721CVE-2026-100723CVE-2026-100722

[ Packages ]Affected open-source packages

• vm2 npmAffected <= 3.12.1 · fixed in 3.12.2 · GHSA-2v2p-6j97-cjg9

[ References ]References

• github.com/patriksimek/vm2/security/advisories/GHSA-2v2p-6j97-cjg9
• www.vulncheck.com/advisories/vm2-before-3.12.2-host-process-termination-via-construct-trap