Safe in the sandbox: security hardening for Cloudflare Workers

What this post added

This post details two key security hardening measures for Cloudflare Workers: 1. The deployment of internal modifications to V8 to use memory protection keys (MPK) to isolate V8 isolates from each other, protecting heap data and preventing cross-isolate memory access in most cases. 2. The adoption and integration of the V8 sandbox, a software-based security boundary that aims to prevent memory corruption attacks from escalating by removing pointers from the heap and utilizing compressed pointers.