Yes, we're discussing though in safe (non-unsafe/normal) Rust here. There is no safe C++, everything in C++ is unsafe by default. Even more unsafe than Rust unsafe, because Rust unsafe still does a lot of the safety measures of normal Rust, but allows only a handful extra things and doesn't disable the borrow checker:
But getting back to the point, the C++ compiler doesn't have a borrow checker, so it can't have a bug in it. So it's on you, as the developer, to take care of all unsoundness.
While in Rust an issue is now filed, and with the fix, every future Rust program gets the fix.
https://doc.rust-lang.org/book/ch20-01-unsafe-rust.html
But getting back to the point, the C++ compiler doesn't have a borrow checker, so it can't have a bug in it. So it's on you, as the developer, to take care of all unsoundness.
While in Rust an issue is now filed, and with the fix, every future Rust program gets the fix.