THJCC CTF 2026 summer
34 challenges with 44 published solutions between them. No writeups were ever filed against this event's listing, so its solutions were found in public repositories instead. Each link is pinned to the commit it was read from.
The event listingMisc9
Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.
Readme Zh
8 official solutionsAlso written up in: jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup
67jail
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Also written up in: jimmy20180130/ctf-writeup
Baritone
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
CTFxck
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Shifting V2
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
SO EZ MISC
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
TeaGod666
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Time Machine
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Cryptography7
Recover a plaintext or a key from something that was supposed to protect it. In practice: identify the scheme, find the parameter the author got wrong, exploit it.
A Million Messages
2 official solutionsAlso written up in: jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup
Forbidden Attack
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Lattice of Doom
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Nonce Sense
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Oracle of Padding
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Schizophrenic Signer
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Two Exponents
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Binary exploitation6
Turn a memory-safety bug in a native binary into control of execution. Usually a stack overflow, a format string, or a heap primitive.
Canary Notes
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Chronicle
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Chronicle Redis Pwn
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
I ate something bad
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Necropet
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Very Security Shell
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Reverse engineering5
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
Also written up in: jimmy20180130/ctf-writeup
Because There is no one Make Reverse So I Create This Chal
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
BlackFrost
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
License
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Xorlocks
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Web5
Reach data or functionality the application meant to keep from you - through its inputs, its tokens, or its trust in the client.
Also written up in: jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup
Who is Whois 2
2 official solutionsAlso written up in: jimmy20180130/ctf-writeup, jimmy20180130/ctf-writeup
Avatar Studio
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Contoso Asset Portal
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
SimpleNotes
1 official solutionAlso written up in: jimmy20180130/ctf-writeup
Uncategorised1
The upstream scoreboard did not say, so neither do we.
Paragraph
1 official solutionAlso written up in: jiegec/ctf-writeups
Forensics1
Recover something from a file, a capture, or a disk image - often from a part of it the format says is unused.
Starry Sky
1 official solutionAlso written up in: jimmy20180130/ctf-writeup