“C is a terrible language for security”.
Only if written wrong...
RUST is looking quite cool. There's a growing and strong argument in favour of re-writing lots of stuff in it.
There's a whole OS (redox?) coming along nicely, with a kernel written in RUST. The speed with which it's been written is pretty impressive.
The language seems to be a happy balance between ideas taken from high level languages and being a suitable systems language.