Daily AlpacaHack

A daily CTF challenge with a fun new puzzle every day

What is Daily AlpacaHack?

We publish one simple, beginner-friendly or educational CTF challenge every day!

Join Anytime

Solve within 24 hours of release to appear on the leaderboard.

Not a Competition

Discussion with friends or AI is welcome (account sharing is prohibited).

Solution Sharing Rules

Sharing solutions is allowed only after 24 hours have passed since release.

Solve stats

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Today's Challenge

Submissions (latest 3)

ham4

SOLVED!

May 10, 1:20 AM

hiikunz

SOLVED!

May 10, 1:10 AM

baumroll1234

SOLVED!

May 10, 12:48 AM

Leaderboard

Period

Try the first challenge

Is this your first CTF? Let's begin by tackling the first challenge released on Daily AlpacaHack.

Upcoming challenges reveal the , , and in advance.

May 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

shiragi

Unrevealed TXT

Misc

Easy

123 solves

serioton

unheard

Misc

Medium

73 solves

minaminao

permission denied

Misc

Hard

76 solves

minaminao

permission denied 2

Misc

Medium

75 solves

admin

Alpaca++

Misc

Welcome

181 solves

tchen

Alpaca Rangers 2

Web

Easy

158 solves

pppp4649

Small N

Crypto

Easy

120 solves

hiikunz

secret-table-2

Web

Medium

119 solves

serioton

do the math

Misc

Medium

100 solves

trimscash

func-array

Pwn

Easy

111 solves

minaminao

permission denied 3

Misc

Medium

101 solves

baumroll1234

Vending Machine

Misc

Easy

135 solves

hiikunz

reused n

Crypto

Medium

94 solves

rsk0315

Bounds Checking

Pwn

Hard

25 solves

serioton

Planned topicLFSR

Rev

Easy

minaminao

Planned topicDocker

Misc

Medium

Coming soon

k0080

Planned topicProcedure Linkage Table

Pwn

Hard

Coming soon

k0080

Planned topicCUDA

Rev

Hard

Coming soon

ptr-yudai

Planned topicStack

Pwn

Hard

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for reused n tadanobutubutu ja reused n 8 hours ago
Writeup for reused n baumroll1234 ja reused n 9 hours ago
Writeup for Daily AlpacaHack 5/3-5/9 kakur41 ja reused n +6 10 hours ago
Writeup for reused n goroshirow ja reused n 10 hours ago
Writeup for Vending Machine baumroll1234 author ja Vending Machine 12 hours ago
Writeup for Vending Machine tadanobutubutu ja Vending Machine 14 hours ago
Daily AlpacaHackに挑戦するつくよみちゃん 05/08 misc/Vending Machine/baumroll1234 tsukuyomi-chan ja Vending Machine 16 hours ago
Daily AlpacaHackに挑戦するつくよみちゃん 05/07 misc/Permission Denied 3/minaminao tsukuyomi-chan ja permission denied 3 16 hours ago
Writeup for Vending Machine nozokare ja Vending Machine 17 hours ago
Writeup for permission denied 3 nozokare ja permission denied 3 17 hours ago

Rows:

Bounds Checking

Topic: Out-of-Bounds WriteReleased: May 10, 2026

25 solves

Pwn

Hard

rsk0315

USER	SOLVED AT
ham4	4 minutes ago
hiikunz	15 minutes ago
baumroll1234	36 minutes ago
baloon	42 minutes ago
fulgens	56 minutes ago
nitcelcius	1 hour ago
blackade	2 hours ago
tet3	3 hours ago
tad	4 hours ago
cyanos	7 hours ago
nomeaning	7 hours ago
tadanobutubutu	7 hours ago
edwowmath	8 hours ago
cocoa	9 hours ago
kurgm	9 hours ago
toomer	9 hours ago
pppp4649	9 hours ago
kakur41	10 hours ago
kurokane-isumi	10 hours ago
bono	10 hours ago
rsk0315	10 hours ago
syn9	10 hours ago
shiro	10 hours ago
umineko	10 hours ago
bsvac	10 hours ago

Rows:

description solves