2026from public repositories
nullcon CTF 2026
8 challenges with 8 published solutions between them. CTFtime has no listing for this event at all, so nothing built on CTFtime can show what it was made of. These writeups were found in public repositories instead. Each link is pinned to the commit it was read from.
Where these writeups liveUncategorised4
The upstream scoreboard did not say, so neither do we.
Asan Bazar
1 official solutionEncodinator
1 official solutionHashchain
1 official solutionHashchain V2
1 official solution
Web2
Reach data or functionality the application meant to keep from you - through its inputs, its tokens, or its trust in the client.
Solve it with:JWT decoder and signature verifierJWT alg=none bypass generatorWeb attack payload catalogJWT secret brute forceLearn: Web attacks and session tokens
Cve Db
1 official solutionMeowy
1 official solution
Cryptography1
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.
Solve it with:Cipher identifier and automatic decoderVigenere cipher solver with automatic key recoveryRSA decryption and attack runnerWiener’s attack on small RSA private exponentsIn-browser hash cracker with rule transformsLearn: Classical ciphers and frequency analysisLearn: RSA and the parameters that break it
Booking Key
1 official solution
Reverse engineering1
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
Solve it with:Strings extractor for binaries and blobsWebAssembly disassemblerJava .class disassemblerPython .pyc bytecode disassemblerLearn: Binary exploitation
Coverup
1 official solution