CVE-2026-47210: vm2 sandbox escape via JSPI-backed Promise `.finally()` species bypass

A sandbox escape vulnerability in vm2 allows arbitrary code execution in the host process when untrusted code is executed with async support on runtimes exposing WebAssembly JSPI (WebAssembly.promising / WebAssembly.Suspending). In the tested configuration, a JSPI-backed Promise can reach Promise.prototype.finally() in a way that bypasses the expected Promise-species hardening and exposes a host-originated rejection object to attacker-controlled species logic, breaking the sandbox boundary.

This is a critical sandbox escape: any application that treats vm2 as a security boundary may be fully compromised.