vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, NodeVM exposes some process-wide observability builtins when they are allowed through require.builtin. The diagnostics_channel, async_hooks, and perf_hooks builtins are not blocked by the dangerous builtin denylist. These modules are process-wide, not sandbox-local. Sandboxed code can use them to observe host application data across the vm2 boundary. This issue has been patched in version 3.11.4.