Jorian on Mythryl: “I made a shorter writeup for the CatGPT challenge during hxp CTF at…”

I made a shorter writeup for the CatGPT challenge during hxp CTF at 39C3! It featured a cool combination of JavaScript injections to escape our context and fix the remaining syntax. Check it out: jorianwoltjer.com/blog/p/ctf/h...

jorianwoltjer.comhxpCTF 2025 - CatGPT | Jorian WoltjerThe hardest web challenge during 39C3's hxp CTF. Auditing RegExes in a PHP library to uncover small gadgets that allow escaping and fixing a JavaScript context.

5/1/26, 9:39 am1 repost5 likes

Post