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.

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Today's Challenge

Submissions (latest 3)

trimscash

SOLVED!

May 18, 2:07 PM

tsukuyomi-chan

SOLVED!

May 18, 2:06 PM

ntanaka

SOLVED!

May 18, 2:04 PM

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🌱

125 solves

serioton

unheard

Misc

Medium

75 solves

minaminao

permission denied

Misc

Hard

77 solves

minaminao

permission denied 2

Misc

Medium

77 solves

admin

Alpaca++

Misc

Welcome🌱

221 solves

tchen

Alpaca Rangers 2

Web

Easy🌱

191 solves

pppp4649

Small N

Crypto

Easy🌱

145 solves

hiikunz

secret-table-2

Web

Medium

139 solves

serioton

do the math

Misc

Medium

110 solves

trimscash

func-array

Pwn

Easy🌱

134 solves

minaminao

permission denied 3

Misc

Medium

108 solves

baumroll1234

Vending Machine

Misc

Easy🌱

163 solves

hiikunz

reused n

Crypto

Medium

112 solves

rsk0315

Bounds Checking

Pwn

Hard

83 solves

serioton

Mirage

Rev

Easy🌱

118 solves

minaminao

hidden service

Misc

Medium

98 solves

tchen

Super Short Python Golf

Misc

Medium

112 solves

minaminao

Equation Cipher

Crypto

Medium

98 solves

tan90909090

curl as a service

Web

Misc

Medium

100 solves

k0080

Please Link This

Pwn

Hard

69 solves

tan90909090

curl as a service 2

Web

Misc

Hard

78 solves

shiragi

Flag for Switch

Web

Easy🌱

108 solves

pppp4649

Planned topicRSA

Crypto

Medium

tchen

Planned topicLFI

Web

Medium

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 curl as a service 2

nitcelcius

curl as a service 2

1 hour ago

コメントを入力 Daily AlpacaHackに挑戦するつくよみちゃん 05/15 web-misc/curl as a service 2/tan90909090

tsukuyomi-chan

curl as a service 2

20 hours ago

Writeup for curl as a service 2

goroshirow

curl as a service 2

22 hours ago

Writeup for curl as a service 2

tadanobutubutu

curl as a service 2

22 hours ago

Writeup for Please Link This

tadanobutubutu

Please Link This

2026/05/17 10:46

Writeup for Please Link This

baumroll1234

Please Link This

2026/05/16 21:20

Writeup for Please Link This

goroshirow

Please Link This

2026/05/16 15:42

Writeup for Daily AlpacaHack 5/4-5/10

labpump

reused n

2026/05/16 13:27

Daily AlpacaHackに挑戦するつくよみちゃん 05/15 web-misc/curl as a service/tan90909090

tsukuyomi-chan

curl as a service

2026/05/15 18:05

Writeup for curl as a service

goroshirow

curl as a service

2026/05/15 15:03

Rows:

hit-and-miss

Topic: RegexReleased: Dec 9, 2025

415 solves

Misc

Easy🌱

ark