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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No solved challenges yet.

Today's Challenge

Submissions (latest 3)

kowerkoint

SOLVED!

Jun 24, 6:58 AM

pppp4649

SOLVED!

Jun 24, 5:08 AM

reid

SOLVED!

Jun 24, 4:53 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.

Jun 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

admin

Half-Year Recap

Misc

Welcome🌱

237 solves

minaminao

Cache Me If You Can

Web

Easy🌱

199 solves

minaminao

vm1

Misc

Medium

95 solves

pppp4649

Small e

Crypto

Easy🌱

134 solves

minaminao

RPS GAME

Misc

Crypto

Medium

96 solves

nozokare

Flag for localhost

Web

Easy🌱

156 solves

tan90909090

C++ flag checker

Rev

Hard

84 solves

shiragi

Guess IP

Misc

Easy🌱

140 solves

nozokare

A Piece of DHKE

Crypto

Medium

81 solves

shiragi

chmod-swapper

Misc

Medium

84 solves

tchen

Alpaca Certification

Web

Easy🌱

155 solves

rsk0315

Floating Equality

Misc

Medium

89 solves

pppp4649

Elliptic Equation

Crypto

Hard

59 solves

tchen

CAuth

Web

Hard

65 solves

minaminao

SITE/2

Web

Easy🌱

117 solves

tan90909090

Xored PNG

Misc

Medium

84 solves

tchen

Looks like Alpacahack

Web

Medium

80 solves

shiragi

Catrunner 2

Misc

Easy🌱

103 solves

minaminao

Flag Printer 20XX

Misc

Medium

61 solves

nozokare

xorshift521

Crypto

Hard

54 solves

k0080

what-is-my-size

Pwn

Hard

63 solves

minaminao

✌️✌️✌️

Crypto

Easy🌱

84 solves

tchen

Secret Renderer

Web

Medium

69 solves

kanon

honk the klaxon

Crypto

Medium

35 solves

colza

Planned topicArchive

Misc

Easy🌱

Coming soon

bubu

Planned topicClient-Side

Web

Hard

pppp4649

Planned topicTBA

Pwn

Hard

Coming soon

admin

Planned topicWelcome

Misc

Welcome🌱

hiikunz

Planned topicMathematics

Crypto

Easy🌱

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Daily AlpacaHackに挑戦するつくよみちゃん 06/23/Secret Renderer/tchen

tsukuyomi-chan

Secret Renderer

15 hours ago

Writeup for ✌️✌️✌️

baumroll1234

✌️✌️✌️

2026/06/22 18:13

Writeup for ✌️✌️✌️

minaminao

author

✌️✌️✌️

2026/06/22 17:14

Daily AlpacaHackに挑戦するつくよみちゃん 06/22/✌️✌️✌️/minaminao

tsukuyomi-chan

✌️✌️✌️

2026/06/22 16:47

Writeup for ✌️✌️✌️

tadanobutubutu

✌️✌️✌️

2026/06/22 15:53

Writeup for what-is-my-size

tadanobutubutu

what-is-my-size

2026/06/22 13:57

Writeup for what-is-my-size

goroshirow

what-is-my-size

2026/06/21 16:19

Writeup for xorshift521

umineko

xorshift521

2026/06/21 04:52

Daily AlpacaHackに挑戦するつくよみちゃん 06/20/xorshift521/nozokare

tsukuyomi-chan

xorshift521

2026/06/20 15:40

Writeup for xorshift521

baumroll1234

xorshift521

2026/06/20 15:22

Rows:

Short Writer

Topic: Out-of-Bounds WriteReleased: Jan 16, 2026

137 solves

Pwn

Hard7.0

k0080

USER	SOLVED AT
mtayo	2026/06/20 09:18
ojun	2026/06/18 01:15
ylz	2026/06/16 03:08
rito	2026/06/09 00:23
sig-255	2026/06/04 10:21
nakamulab	2026/06/01 08:17
miraicantsleep	2026/05/25 01:58
kurokane-isumi	2026/05/10 03:08
muhammed	2026/05/06 10:04
baloon	2026/05/03 11:11
kotatu	2026/05/01 06:52
claustra01	2026/04/29 14:07
figaro-san	2026/04/22 13:21
kitatai	2026/04/12 08:20
koufu193	2026/03/25 08:32
rrrr	2026/03/24 23:28
over20	2026/03/24 11:56
stepbystepbymyself	2026/03/23 13:25
singetu0096	2026/03/22 16:56
kurenaif	2026/03/22 08:12
desp41r	2026/03/20 03:43
popopo	2026/03/08 14:40
tikisan0531	2026/03/01 09:32
ahnmo	2026/02/28 10:10
tara	2026/02/22 03:12