Allocation of Resources Without Limits or Throttling Affecting vm2 package, versions <3.11.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about Allocation of Resources Without Limits or Throttling vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-JS-VM2-16438976
- published7 May 2026
- disclosed7 May 2026
- creditkoDove
Introduced: 7 May 2026
NewCVE-2026-44004 (opens in a new tab)How to fix?
Upgrade vm2 to version 3.11.0 or higher.
Overview
vm2 is a sandbox that can run untrusted code with whitelisted Node's built-in modules.
Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling through the Buffer.alloc family in lib/setup-sandbox.js. An attacker can crash the host process by supplying a large allocation size to Buffer.alloc, Buffer.allocUnsafe, Buffer.allocUnsafeSlow, or the deprecated Buffer(N) / new Buffer(N) forms inside sandboxed code.
These calls execute as a single synchronous host C++ allocation, so a small sandbox payload can force a large RSS spike that exhausts memory in constrained deployments such as containers or serverless runtimes.
PoC
const { VM } = require("vm2");
const vm = new VM({ timeout: 5000 });
// Buffer.alloc bypasses timeout — allocates 100MB on host heap
const result = vm.run(`Buffer.alloc(1024*1024*100).length`);
console.log(result); // 104857600 — timeout had no effect
// Control test — JavaScript loop IS caught by timeout
try {
vm.run(`var a=[]; while(true) a.push(1)`);
} catch(e) {
console.log(e.message); // "Script execution timed out after 5000ms"
}