2026-04-22 7 min read Rust Workers run on the Cloudflare Workers platform by compiling Rust to WebAssembly, but as we’ve found, WebAssembly has some sharp edges. When things go wrong with a panic or an unexpected abort, the runtime can be left in an undefined state. For users of Rust Workers, panics were historically fatal, poisoning the instance and possibly even bricking the Worker for a period of time. While we were able to detect and mitigate these issues, there remained a small chance that a Rust Worker would unexpectedly fail and cause other requests to fail along with it. An unhandled Rust abort in a Worker affecting one request might escalate into a broader failure affecting sibling requests or even continue to affect new incoming requests. The root cause of this was in wasm-bindgen, the core project that generates the Rust-to-JavaScript bindings Rust Workers depend on, and its lack of built-in recovery semantics.…