Comment by lern_too_spel

> This may never exist

It's existed for years. https://chromium.googlesource.com/chromium/src/+/HEAD/third_...

Similarly, the JPEG XL decoder Chromium integrated is written in Rust, eliminating large classes of exploitable errors.

> Haven't we seen related vulnerabilities?

Repeatedly. That's why browser vendors are careful about adding new image decoders, and no, Qubes does not solve the problem.