Critical · published September 17, 2026
vm2 is a sandbox for running untrusted Node.js code. In versions >= 3.11.4 and <= 3.11.6, the NodeVM constructor computes `hasRealRequireConfig` with `typeof requireOpts === 'object' && requireOpts !== null`, so an array-shaped `require` value (for example `require: []`) satisfies the guard that is meant to reject nesting without an explicit require configuration. `makeResolverFromLegacyOptions()` then destructures the array into undefined option fields and returns a resolver containing only `NESTING_OVERRIDE.vm2`. As a result, an attacker who can supply JavaScript executed by a NodeVM configured with truthy `nesting` and an array-shaped `require` (e.g. `new NodeVM({nesting: true, require: []})`) can require the host `vm2` module, create an inner NodeVM with an attacker-chosen builtin allowlist (such as `child_process`), and execute arbitrary commands with the privileges of the host Node.js process, escaping the sandbox. Outer builtin restrictions do not constrain the attacker-created inner NodeVM. This issue is fixed in vm2 3.11.7.