CAT CTF 26
- Starts
- Ends
- Runs for
- 24 hours
- Format
- Jeopardy (online)
- Rating weight
- Unrated by CTFtime
- Teams registered
- 7
Run by 0xL4ugh.
What the organisers say
Welcome to CAT CTF 26 — the third edition of CAT CTF! This beginner-friendly Capture the Flag competition is organized by the CAT Reloaded Student Activity Club at Mansoura University. Our main goal is to help Egyptian university students strengthen their cybersecurity skills, but the event is open to participants from all around the world. Everyone is welcome to join, learn, and compete!
Prep briefing
What past editions were made of
Counted across 19 challenges from 2026, using the categories the scoreboards themselves used. Two things to hold in mind while reading it. The archive indexes challenges that someone published a solution to, not whole scoreboards, so this is the shape of what people wrote about rather than of everything that was set. And where a scoreboard gave no category the challenge lands in misc, so a large misc slice means “unlabelled” rather than “miscellaneous”.
- crypto 26%(5)
- misc 26%(5)
- rev 21%(4)
- pwn 21%(4)
- forensics 5%(1)
What to have open when it starts
Crypto
Have the cipher identifier open on the first paste. Most of the round-one crypto is a classical cipher or an RSA parameter mistake, and both are recognised faster than they are solved.
- Cipher identifier and automatic decoder
- RSA decryption and attack runner
- XOR cipher decoder and key recovery
- Vigenere cipher solver with automatic key recovery
- Modular arithmetic and number theory toolkit
New to this? Read Classical ciphers and frequency analysis, XOR and the cost of reusing a key, RSA and the parameters that break it
Misc
Misc is whatever did not fit, which in practice means encodings and esolangs. Identify, do not guess.
- Cipher identifier and automatic decoder
- Recipe builder: chain decodes and transforms
- Brainfuck and esolang decoder
- Base64 decoder and encoder
- Regex tester with match offsets and capture groups
New to this? Read Recognising encodings, Misc and esoteric languages
Reversing
Identify the binary before you open it. Knowing it is a .pyc, a JAR or a stripped ELF decides the next hour.
- ELF, PE and Mach-O binary analyzer
- Strings extractor for binaries and blobs
- Python .pyc bytecode disassembler
- Java .class disassembler
- WebAssembly disassembler
New to this? Read Reverse engineering
Pwn
Get the offset and the libc base mechanically, so the thinking is spent on the chain rather than on arithmetic.
- Cyclic pattern generator and offset finder
- Buffer overflow offset finder
- Libc base address calculator
- ROP gadget finder
- Pwntools exploit script generator
New to this? Read Binary exploitation
The challenges people wrote about most
From previous editions, ordered by how many published solutions each attracted. Reading two solutions to one of these is the closest thing to a warm-up for this event that exists.
- Battleshipmisc · 2026 · 1 writeup
- Brown Ravengemisc · 2026 · 1 writeup
- Captain Morgenrev · 2026 · 1 writeup
- Crazy Curvescrypto · 2026 · 1 writeup
- Cursed Mapforensics · 2026 · 1 writeup
- Favrt Langrev · 2026 · 1 writeup