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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)

SOLVED!

May 22, 9:45 PM

SOLVED!

May 22, 9:00 PM

SOLVED!

May 22, 7:46 PM

Leaderboard

Period

Try the first challenge

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

AlpacaHack 2100

Upcoming challenges reveal the , , and in advance.

May 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

27

shiragi

Misc

Easy🌱

128 solves

28

serioton

Misc

Medium

77 solves

29

minaminao

permission denied

Misc

Hard

80 solves

30

minaminao

permission denied 2

Misc

Medium

81 solves

1

admin

Misc

Welcome🌱

243 solves

2

tchen

Alpaca Rangers 2

Web

Easy🌱

206 solves

3

pppp4649

Crypto

Easy🌱

153 solves

4

hiikunz

Web

Medium

144 solves

5

serioton

Misc

Medium

114 solves

6

trimscash

Pwn

Easy🌱

144 solves

7

minaminao

permission denied 3

Misc

Medium

112 solves

8

baumroll1234

Vending Machine

Misc

Easy🌱

174 solves

9

hiikunz

Crypto

Medium

114 solves

10

rsk0315

Bounds Checking

Pwn

Hard

84 solves

11

serioton

Rev

Easy🌱

122 solves

12

minaminao

Misc

Medium

101 solves

13

tchen

Super Short Python Golf

Misc

Medium

115 solves

14

minaminao

Equation Cipher

Crypto

Medium

99 solves

15

tan90909090

curl as a service

Web

Misc

Medium

109 solves

16

k0080

Please Link This

Pwn

Hard

75 solves

17

tan90909090

curl as a service 2

Web

Misc

Hard

86 solves

18

shiragi

Flag for Switch

Web

Easy🌱

150 solves

19

pppp4649

Crypto

Medium

99 solves

20

tchen

Web

Medium

103 solves

21

kakur41

Python:Impossible

Misc

Medium

99 solves

22

nozokare

Time Travelers' OTP

Web

Medium

71 solves

23

minaminao

Crypto

Hard

17 solves

24

Planned topicCUDA

Rev

Hard

25

Planned topicPath Traversal

Misc

Easy🌱

26

Planned topicRSA

Crypto

Medium

27

Planned topicCSP

Web

Medium

28

Coming soon

29

Planned topicRSA

Crypto

Medium

30

Planned topicXSS

Web

Hard

31

Planned topicStack

Pwn

Hard

Want a harder challenge?

Writeups

Daily AlpacaHackに挑戦するつくよみちゃん 05/22 web/Time Traveler's OTP/nozokare

tsukuyomi-chan

ja

Time Travelers' OTP

1 hour ago

Writeup for Time Travelers' OTP

tadanobutubutu

ja

Time Travelers' OTP

2 hours ago

Writeup for Time Travelers' OTP

baumroll1234

ja

Time Travelers' OTP

6 hours ago

Writeup for Python:Impossible

goroshirow

ja

Python:Impossible

15 hours ago

Daily AlpacaHackに挑戦するつくよみちゃん 05/21 misc/Python: Impossible/kakur41

tsukuyomi-chan

ja

Python:Impossible

2026/05/21 17:18

Writeup for Python:Impossible

tadanobutubutu

ja

Python:Impossible

2026/05/21 15:23

Writeup for Kakuzuke

tadanobutubutu

ja

2026/05/20 19:07

Daily AlpacaHackに挑戦するつくよみちゃん 05/20 web/Kakuzuke/tchen

tsukuyomi-chan

ja

2026/05/20 16:03

Writeup for Kakuzuke

goroshirow

ja

2026/05/20 15:39

Writeup for Emojify

paulayground

ko

2026/05/20 15:17

Rows:

Alpaca Rangers 2

Topic: File ReadReleased: May 2, 2026

206 solves

Easy🌱

by

tchen

Tags

Alpaca Rangers is back! (Note: You don't necessarily have to solve Alpaca Rangers first)

Beginner Hint

The goal of this challenge is to read the contents of /flag.txt
Is the replace function enough to prevent directory traversal attacks?

alpaca-rangers-2.tar.gz

description solves writeups