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)

toomer

SOLVED!

Jul 25, 4:06 PM

kakur41

SOLVED!

Jul 25, 4:02 PM

pppp4649

SOLVED!

Jul 25, 3:43 PM

Leaderboard

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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.

Jul 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

tchen

Nano Services

Web

Medium

88 solves

minaminao

Super Short System Exit

Misc

Medium

83 solves

admin

Alpaca Nation

Misc

Welcome🌱

250 solves

hiikunz

Flag is A+B

Crypto

Easy🌱

149 solves

tchen

Lucky Redirect

Web

Easy🌱

144 solves

hiikunz

Renda

Rev

Medium

111 solves

tchen

IP Blocked Secret

Web

Hard

66 solves

minaminao

duplicate entry

Misc

Easy🌱

144 solves

hiikunz

Lazy RSA

Crypto

Medium

104 solves

minaminao

Let's Poly1305!

Crypto

Medium

76 solves

shiragi

private method

Misc

Easy🌱

136 solves

hiikunz

secret-table-3

Web

Medium

84 solves

baumroll1234

A slight mistake

Pwn

Hard

69 solves

tan90909090

Compile time flag checker

Rev

Hard

56 solves

baumroll1234

Redirecting to Login Page

Web

Easy🌱

150 solves

tchen

You've Got Shlex

Misc

Medium

87 solves

minaminao

Let's Poly1305! 2

Crypto

Hard

64 solves

tchen

Beat the Alpaca Lord

Web

Medium

90 solves

pppp4649

biribiri

Crypto

Medium

86 solves

tchen

Greetings CGI

Web

Hard

70 solves

hiikunz

no win func

Pwn

Hard

72 solves

tchen

Alpaca Blog

Web

Easy🌱

113 solves

tan90909090

NOP Variant

Rev

Misc

Medium

65 solves

ark

jinjail

Misc

Hard

42 solves

tchen

True or False

Misc

Medium

67 solves

minaminao

Cache Me If You Can 2

Web

Hard

46 solves

k0080

what-is-my-pointer

Pwn

Hard

42 solves

tchen

Greetings i18n

Web

Hard

6 solves

tchen

Planned topicHTTP

Web

Easy🌱

Coming soon

admin

Planned topicWelcome

Misc

Welcome🌱

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for Cache Me If You Can 2 (with PowerShell)

nitcelcius

Cache Me If You Can 2

1 hour ago

Writeup for True or False

baumroll1234

True or False

2026/07/23 20:57

Writeup for True or False

nirvana

True or False

2026/07/23 15:05

Writeup for jinjail

goroshirow

jinjail

2026/07/23 07:16

Writeup for NOP Variant

umineko

NOP Variant

2026/07/22 04:11

Daily AlpacaHackに挑戦するつくよみちゃん07/21/NOP Variant/tan90909090

tsukuyomi-chan

NOP Variant

2026/07/21 16:33

Writeup for Alpaca Blog

nirvana

Alpaca Blog

2026/07/21 13:38

Writeup for Alpaca Blog

baumroll1234

Alpaca Blog

2026/07/20 21:53

Writeup for no win func

ojun

no win func

2026/07/19 15:04

Writeup for You've Got Shlex (shlex only)

kurimochi

You've Got Shlex

2026/07/19 05:58

Rows:

Greetings i18n

Topic: PythonReleased: Jul 26, 2026

6 solves

Web

Hard6.5

tchen

Only two languages are supported for now.

Beginner Hint

str.format is usually considered unsafe when the template string comes from user input. How can you abuse this?
If you want to know which attributes are available on a Python object, you can run the code locally and use print(dir(obj)).

greetings-i18n.tar.gz

description solves