vm2 CLI provides no sandbox isolation - host-realm require() is reachable from sandboxed scripts

### Summary The `vm2` command-line tool installed by `npm install -g vm2` and documented in the README's "CLI" section runs the supplied script under `NodeVM` with `require:{external:true}` and no `root` / `context` / `builtin` configured. With these defaults the resolver loads every relative or absolute `require()` target through the **host** `require()` function, executing the attacker's module body in the host Node.js process before the result is ever proxied back into the sandbox. A single attacker-controlled file passed to `vm2 ./script.js` can call `require(__filename)` to re-execute itself in host realm and reach `fs`, `child_process`, etc. The documented sandbox runner is therefore equivalent to `node ./script.js`. No additional files, flags, or user interaction are required. ### Details The vulnerability lets a **malicious sandboxed script** - the file argument to the documented `vm2 ` CLI - execute arbitrary code in the **host Node.js process**, crossing the sandbox → host boundary that vm2 is meant to enforce. #### Vulnerable code path 1. **Source** - `bin/vm2:3` → `lib/cli.js:7-18`. `process.argv[2]` is the attacker-authored script path. The CLI invokes: ```js NodeVM.file(path, { verbose: true, require: { external: true } }); ``` Without `require.root`, `require.context`, nor `require.builtin`. 2. **Hop** - `lib/nodevm.js:618-636`. `NodeVM.file` reads the file and calls `new NodeVM(options).run(body, resolvedFilename)`. 3. **Hop** - `lib/nodevm.js:335` → `lib/reso