CU school CTF 2026
67 challenges with 131 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 listingMisc20
Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.
Gopher
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Meshtastic
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Nanofactory Tape
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
New Bot
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Night Tubes
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Nightpacket
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Broken Phone
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Free Online Games
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Icq Bot
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Config
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Gocaptcha
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Imaginator
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Moderation
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Oscar
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Proto
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Cryptography9
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.
Also written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Maintenance Ratio
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Orbital Oracle
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Scriptorium Oracle
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Server
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Client
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Geek Wall
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Forensics7
Recover something from a file, a capture, or a disk image - often from a part of it the format says is unused.
Ransomware
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Not Hidden
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Binary exploitation7
Turn a memory-safety bug in a native binary into control of execution. Usually a stack overflow, a format string, or a heap primitive.
Relay Ledger
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Wire Office
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Zamorozki
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Insanity
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Space Station
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Kalyna Transformations
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
OSINT6
Answer a question about the real world from public sources. The work is pivoting between identifiers, not exploiting anything.
Antispoofing V2
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Far Far Away
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Frosty
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Landscape
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Lost Friend
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Reverse engineering6
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
Hollerith Requiem
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Jacquard Nocturne
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Scope Wake
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Model
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Ottepel
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Build Pack
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Web5
Reach data or functionality the application meant to keep from you - through its inputs, its tokens, or its trust in the client.
Courier District 98
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Nightline99
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Radioshop
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Nightline Core
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Uncategorised4
The upstream scoreboard did not say, so neither do we.
Silver Melon
3 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Archive Noise
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Generate Dc Bots
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Test Dummy Bot
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public
Steganography3
Find the payload hidden inside a carrier that looks ordinary. Bit planes, appended data, metadata, and audio spectrograms.
Weight
2 official solutionsAlso written up in: CU-CUT/cu-school-ctf-2026-public, CU-CUT/cu-school-ctf-2026-public
Also written up in: CU-CUT/cu-school-ctf-2026-public
Generate
1 official solutionAlso written up in: CU-CUT/cu-school-ctf-2026-public