Critical Sandbox Escape in isolated-vm via Type Confusion

A critical security flaw (GHSA-864f-rcv7-6rh4) has been identified in isolated-vm, a widely used Node.js library for sandboxing untrusted code in AI and automation platforms. The vulnerability is a type confusion bug in the C++ binding layer that marshals data across the V8 Isolate boundary. While the V8 isolation itself remained intact, the 'glue code' responsible for handling serialized objects was found to be susceptible to exploitation through stateful JavaScript getters.

Technically, the vulnerability stems from a Time-of-Check/Time-of-Use (TOCTOU) gap during the processing of the 'transferList' option in the ExternalCopy constructor. Attackers can provide a malicious getter that returns a valid ArrayBuffer during the validation phase but an arbitrary integer during the transfer phase, leading to memory corruption. This can be escalated from a simple denial-of-service (SIGSEGV) to full remote code execution on the host process.

This discovery is highly significant for the AI and automation sectors, as isolated-vm is a foundational security control for platforms like n8n, Activepieces, and Mastra AI. Any application sharing even a single 'ivm.Reference' with an isolate is vulnerable. Organizations must upgrade to versions 7.0.1 or 6.2.0 immediately to mitigate the risk of sandbox escapes.