The listed browsers are basically skins on top of the same chromium base.

It’s why Firefox and Safari as so important despite HN’a wish they’d go away.

Firefox is safe from this because their CSS handling was the first thing they rewrote in Rust.

Firefox and Safari are fine in this case, yeah.

It's pretty hard to have an accidental a use after free in the FireFox CSS engine because it is mostly safe Rust. It's possible, but very unlikely.