CVE-2026-92955

vm2 before 3.11.8 contains a sandbox escape in its NodeVM class that exposes the host environment's __proto__ getter/setter to sandboxed code via console._stdout and console._stderr. An attacker who can run code inside the sandbox uses these streams to reach host objects, overwrites EventEmitter.prototype.emit, and triggers process events to execute code with full process context, bypassing vm2's code generation restrictions. This yields complete compromise of the host Node.js process, reflected in the maximum CVSS 4.0 score of 10 with full confidentiality, integrity, and availability impact. Any Node.js application using a vulnerable vm2 version to execute untrusted or semi-trusted code in NodeVM is affected. No public proof-of-concept, CISA KEV listing, or confirmed in-the-wild exploitation is currently known.

What to do: Upgrade vm2 to version 3.11.8 or later wherever the library runs untrusted code in NodeVM. Since vm2 has a long history of sandbox escapes and is effectively unmaintained, plan a migration to a stronger isolation alternative such as isolated-vm or process/OS-level sandboxing. As interim mitigation, prevent sandboxed code from reaching console._stdout/_stderr (e.g., neutralize or replace the console object passed into the sandbox) and audit applications for any reliance on vm2 NodeVM with attacker-controlled input.