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.

Affected: npm: vm2

## Summary

The `NodeVM` constructor computes `hasRealRequireConfig` using `typeof requireOpts === 'object' && requireOpts !== null`, so `require: []` bypasses the guard intended to reject `nesting` without an explicit require configuration. `makeResolverFromLegacyOptions()` then destructures the array to undefined option fields and returns a resolver containing only `NESTING_OVERRIDE.vm2`. Any attacker whose JavaScript is executed by a downstream `NodeVM` configured with `{nesting: true, require: []}` can load the host `vm2` module, create an inner `NodeVM` with an attacker-selected builtin allowlist, and execute commands as the host process. No equivalent plain-object validation exists in `makeResolverFromLegacyOptions()`.

Array is converted into the vm2-only resolver: https://github.com/patriksimek/vm2/blob/54b54b74a382577f0bcd0538c5bf99acdcd7f53b/lib/resolver-compat.js#L205-L226

Nesting loader returns the host VM constructors: https://github.com/patriksimek/vm2/blob/54b54b74a382577f0bcd0538c5bf99acdcd7f53b/lib/nodevm.js#L640-L645

## Proof of Concept

Preconditions:

- The host creates `NodeVM` with truthy `nesting` and array-shaped `require`. - The attacker can supply JavaScript executed by that `NodeVM`.

```javascript 'use strict';

const {NodeVM} = require('./index.js');

const outer = new NodeVM({nesting: true, require: []}); const result = outer.run(` const {NodeVM} = require('vm2'); const inner = new NodeVM({require: {builtin: ['child_process']}}); module.exp…