Also, the reason this is a CVE is because Rust itself guarantees that calling commands doesn't evaluate shell stuff (but this breaks that guarantee). As far as I know C/C++ makes no such guarantee whatsoever.
C++ has no guarantees built into stdlib but frameworks like Qt provide safe access - the ecosystem has options. C++ itself is quite a simple language, most of the power comes out of toolsets and frameworks built on top of it.
That’s certainly not the case, because that’s like saying the issue is with Rust’s string slices. I think you may have missed the part of the issue where batch scripts require additional escaping due to Windows’ command handling. It’s a ridiculous design of the Windows API system, which is also why (almost?) every language they tested was vulnerable, so it would be actually very outstanding if Qt prevented this.
For C++ devs not using Qt it’s just another footgun they’ll likely keep introducing security issues with as well. But if you do use Qt, I think it’s better to double-check since it may also require a patch.