Project Sekai CTF

SekaiCTF 2026 is officially over! Thank you to all participants this year, and congratulations to our winners: 🥇 @TeamH4C__ 🥈 @w4llz_Team 🥉 AAAA 🏆 F1ux 🏆 Cow Pig Once again, thanks everyone for playing!

This also marks the conclusion of SekaiCTF 2026. We'd like to thank again to our sponsors, @zellic_io @osec_io @trailofbits @vector35, and @googlecloud for their generous support. Thanks everyone for playing!🎵 (4/4)

[+] Minions in 16k Winners: 1. m_afj: mrfuzzypants.writeups-me.workers.dev/challenge?titl…, mrfuzzypants.writeups-me.workers.dev/challenge?titl… 2. ilovecandy69: joksdz.github.io/website/#/blog… 2. lowrule: files.catbox.moe/9mn9ax.pdf [+] Binary Ninja Personal License: - xtea418: Misc - ▶ Sanity Check sandbox.rip/sekai-sanity-c… (3/4)

- devilhunter_55: Crypto – apbq-rsa-iv drive.google.com/drive/folders/… - el_s1na: Pwn – ppp epsilons1na.github.io/posts/sekai_ct… - @hxuu0: Web – <\w+ vhxuu.xyz/blog/sekai26/l… - mushsh: Web – EnD mushroom.cat/ctf/http-desyn… (2/4)

🧵We would like to announce the writeup competition winners: [+] Cash Prize Winners: - .sestoelemento: Blockchain – Open World pnasis.gitlab.io/posts/sekaictf… - kiinzu: Blockchain – PP Farming (1 & 2) kiinzu.io/blog/sekaictf-… (1/4)

We're launching a $100,000 fund to save CTFs.

R3CTF 2026 has come to a successful close. Please join us in congratulating this year’s award-winning teams! 🥇 BBBB 🥈 EQST 🥉 @ProjectSEKAIctf Thank you to our sponsors @nebusecurity @osec_io @zellic_io @vector35 @googlecloud Hope see you next year!

Thanks to @AnthropicAI for keeping the promise!

Running a CTF for thousands of players without things falling over is no small feat. @es3n1n wrote up exactly how we did it: sekai.team/blog/sekaictf-…

For this (maybe last) year of SekaiCTF I made a fullchain challenge, chaining together an 0-day in ladybird/libjs, an 0-day qemu TCG LPE and a n-day qemu escape: qyn.app/blog/sekaictf-… We also re-released another challenge with a running bounty until next week!

24 hours into #SekaiCTF 2026. A few challenges remain unsolved, come and pwn them at ctf.sekai.team :)

SekaiCTF 2026 has officially started! You can still register now at ctf.sekai.team.

Finally, thanks to @XCTF_League for the partnership! As a reminder, the winning team of SekaiCTF 2026 will earn a spot in the 11th XCTF Finals.

Big thanks to @googlecloud for the infrastructure support! Learn more about Google Cloud Platform at cloud.google.com

Big thanks to all of our generous sponsors for #SekaiCTF 2026! All sponsors will be showcased in the following thread, in no particular order.🧵

@ethereum @SuiNetwork @StellarOrg @ton_blockchain

In SekaiCTF 2026, our blockchain challenges feature Ethereum, Sui, Stellar & TON — each with a 100 USDT bounty for first blood. There will also be two 100 USDT prizes reserved for the best writeups. Remember to register at ctf.sekai.team! #SekaiCTF #Teaser