Not true, it can also occur in C++, Zig, and assembly language.

Or Rust, when not sticking exclusively to safe Rust, but this is not really possible in many systems programming scenarious.

Golang, C# and even Java does have its exploits.

Maybe just Algol68 and Rust can withstand this, among ADA. And PL/1 under Multics.

Firefox it's written in Rust.

No it's not. Yes it contains a lot of Rust, but it's still mostly C++.