Yes it does - qemu-img is written in C. The two programs we found exploitable were written in Python and C. They are written in "satisfactory" languages. Bash is not involved. Yet both suffer exploits because of \n (and other) characters in filenames.

The issue you refer to is in a poorly formed, ad-hoc serialization format. It has nothing to do with representation of variables at runtime. It has nothing to do with the language.

It is a programming error, not an inherent flaw in the language.