Running firefox 4 (or any other comparably old browser), this would be the least of your security problems, it's not even RCE. The stream of discovered vulnerabilities is constant.
What's your point? Do you really think I was suggesting that people are still running Firefox 4?
When WebGL was first implemented in Firefox - long ago - it shipped with serious security flaws. This struck many people as sadly predictable, as graphics APIs like OpenGL are not intended to be accessible from untrusted code. WebGPU seems awfully similar to WebGL in this respect: it's trying to wrap a low-level graphics API in a secure sandboxed API. This isn't the equivalent of a routine addition like a new feature in CSS.
The point was that seen from the future, old browser versions are always full of holes in all kinds of features, more in new features than old ones, we should fix the systemic problems that make browsers so ridden with vulnerabilities.
But yes I am guilty of some whataboutism here, WebGL did have some unique problems and WebGPU devs hopefully learn from them.
