Vulnerability · Published Sep 17, 2026 · Assigned by VulnCheck

CVE-2026-92942vm2 before 3.11.7 Timeout Bypass via FinalizationRegistry

High 7.5

In plain English

A high-severity uncontrolled resource consumption in vm2 from patriksimek. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.5%top 57.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

vm2 before 3.11.7 (affected versions <= 3.11.6) does not enforce the VM({ timeout }) option on code executed outside the synchronous VM#run() call. The timeout only wraps the single call to _runScript() via doWithTimeout() in lib/vm.js, and FinalizationRegistry and WeakRef are exposed to sandboxed code unmodified (they are not among the hardened globals in lib/setup-sandbox.js). Sandboxed code can register a FinalizationRegistry cleanup callback against an object and then drop the only strong reference to it; vm.run() returns within the configured timeout, but when the V8 garbage collector later reclaims the object it invokes the sandboxed cleanup callback outside any vm2 timeout accounting. A busy loop in that callback blocks the host event loop for an unbounded period, resulting in denial of service. The time of invocation depends on the garbage collector (e.g. under memory pressure or with --expose-gc).

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	vm2	3.11.7	GHSA-r4fx-v8hh-22mv

Affected products (as reported)

Vendor	Product	Versions
patriksimek	vm2	0 – before 3.11.7

Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

GitHub Security Advisory (GHSA-r4fx-v8hh-22mv) vendor-advisory
VulnCheck Advisory: vm2 before 3.11.7 Timeout Bypass via FinalizationRegistry third-party-advisory