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.