It is unfortunate that there is no web browser in a memory safe language. As I understand, both Chromium and Firefox use C++, although Firefox partly uses Rust. This has put billions of people at risk.

This post is about a logic bug that could have happened in any language

One of the biggest security holes is the JIT engine, rewriting it in Rust or any other language wouldn't make a difference, since it is effectively an inner platform.

This bug is a logic error iiuc so language wouldn't help.

Servo project is active and probably usable in a year or two (but as others have said this bug is different)