National Cyber League: A Serious Critique
A list of problems for Cyber Skyline to resolve.
Attacking MuJS: Breaking a JS engine with type confusion and an integer overflow.
Albatross: Breaking out of pyjail with your hands tied.
Writeup to redpwnctf's Albatross challenge, where you'd need to take advantage of a python 'eval' without using ASCII characters, strings, and no python builtin functions.