Fugu Jailbreak [ untethered ]

Fugu Jailbreak

Fugu jailbreak is an open source untethered jailbreak based on the checkm8 exploit. It was developed by security researcher Linus Henze from Koblenz, Germany. Fugu14 combined with unc0ver Jailbreak as well. Also read about the latest Fugu15 for iOS 15 – iOS 15.4.1.


iOS versions – iOS 14.5.1, iOS 14.5, iOS 14.4.2, iOS 14.4.1, iOS 14.4, iOS 14.3

Devices – iPhone XR, iPhone XS, iPhone XS Max, iPhone 11, iPhone 11 Pro, iPhone 11 Pro Max, iPhone SE 2, iPhone 12 mini, iPhone 12, iPhone 12 Pro, iPhone 12 Pro Max, iPad 8, iPad Air 2, iPad Air 3, iPad 9, iPad Air 4

Download Fugu14

Even though Fugu14 was released to the public, it is still on the developer level. You cannot use the Fugu14 easily. So you need to download and install the following tools to set up the Fugu 14.





iOS Firmware


Note – Fugu14 would be installed automatically when unc0ver jailbreak app side-loading via the AltStore v1.4.8

How to setup Fugu 14

Step 01 – Unzip downloaded fugu14 archive file.

Step 02 – Open it, go to arm > iOS > Fugu14App > Fugu14App.xcodeproj.

Step 03 – Tap on the “trust and open” from the prompt message. Now open the xcode project.

Step 04 – Meanwhile, connect the iPhone to the computer. Go to fugu14app > Targets> Signing & Capabilities > Team. If there is no Apple ID, tap on add an account then follow on-screen instructions.

Step 05 – If you get the error message, tap bundle Identifier and add some random text. It will fix the error. 

Step 06 – Close the Xcode window. Again go to the Fugu14-master folder. Find the ‘ios_install.py’ and run it. Type cd and drag the fugu 14 master folder into the terminal window to update the file path.

Step 07 – Tap Enter. It will get a ‘Welcome to the Fugu14 iOS installer’ message on the terminal window.

Step 08 – Check whether you have the requirements listed in the terminal window. Especially if you have an iproxy and iDevice installer, tap enter to continue.

Step 09 – It will ask some facts. Tap Y for “Do you want to build a jailbreak?”

Step 10 – Then it will ask “ What is the name of your iOS signing certificate?” Open altstore and go to your iPhone Settings > General>Device Management. Go to Apple ID, tap on it, you will see the iOS signing certificate name, type it on the terminal.

Step 11 – At the moment, it will be compiling the jailbreak & wait for the message **BUILD SUCCEEDED**

Step 12 – Rename the downloaded ipsw file extension to .zip. Then extract it. Find the largest dmg file from the extracted folder. Just double click to mount the file.

Step 13 – Again go to the terminal window. Type the part of the dmg file. You might get a “mount path not valid” error. If so, remove the slashes, then tap enter. It will show the created IPA.

Step 14 – Make sure the iPhone is connected to Mac. Now tap enter to continue and Fugu14 will start the sideloading process to your iPhone. Fugu14 will show an untrusted developer message. Go to Settings > General > Device Management. You can see Apple development there, tap to trust the app. Fugu14 will open.

Step 15 – Tap on the ‘Setup Fugu14’. Once completed the process through the iPhone,  go to the terminal window again. Tap enter.  It will display ‘Open the Fugu14App again following the on-screen instructions! message.

Step 16 – Reopen Fugu14 n from the iPhone. Go ahead according to the on-screen instructions.

Step 17 – Again go to the Terminal Window. Run the following commands via new terminal windows.

iproxy 1337 1337

Nc localhost 1337

Step 18 – Make sure to whether it works type bash on the terminal windows.

Well done! Now you have finished the Fugu setup.

Important  Facts of Fugu14
  • Fugu download online jailbreak support not available
  • Fugu does not support iOS 14.6 onwards. Get fugu alternatives.
  • MAC supported computer based jailbreak
  • Kernel exploit is extremely reliable
  • Fugu is still incomplete
  • Not supported for A9-A11 devices. (iPhone X and older) Use Fugu Alternative.

Fugu15 ( iOS 15 – iOS 15.4.1)

Fugu developer Linus Henze talks about  “The Journey to Jailbreaking iOS 15.4.1.” He will shows “how it is possible to jailbreak iOS 15.4.1” at the Mac Security Conference v5.0 to be held on Oct 6th-7th  in Spain, Europe.

Already there is Cheyote jailbreak developing for iOS 15 – iOS 15.1.1 by Coolstar. But Linuz says iOS 15.1.1 is not the last jailbreakable version. He is going to explain new mitigation on iOS 15.2 – iOS 15.4.1. So there is a big chance to release Fugu 15 for iOS 15 – iOS 15.4.1 Jailbreak by Linus Henze. It might take some time because still he hasn’t demonstrated it. After he demonstrated at the conference he might attend for public release. 

However, iOS 15 – iOS 16 haven’t untethered or semi-untethered jailbreak tools yet. But there are jailbreak solutions like Zeon.

Find more details from the following pages. 

iOS 15 – iOS 15.0.2 Jailbreak

iOS 15.1 / iOS 15.1.1 Jailbreak

iOS 15.2 / iOS 15.2.1 Jailbreak

iOS 15.3 / iOS 15.3.1 Jailbreak

iOS 15.4 / iOS 15.4.1 Jailbreak

iOS 15.5 Jailbreak

iOS 15.6 / iOS 15.6.1 Jailbreak

iOS 16 Jailbreak ( Beta )

Fugu for iOS 14.6 – iOS 14.8.1

Currently, Fugu jailbreak is not supported for iOS 14.6 – iOS 14.8.1 versions. There is Checkra1n jailbreak tool available for iOS 14.6 – iOS 14.8.1. Also, unc0ver jailbreak supports iOS 14.6 – iOS 14.8 only for A12/A13 devices.

Visit the following pages for more information.

iOS 14.6 Jailbreak

iOS 14.7 / iOS 14.7.1 Jailbreak 

iOS 14.8 / iOS 14.8.1 Jailbreak

Unc0ver with Fugu14

The most important thing is when Fugu 14 released, Unc0ver v7.0.0 added support for iOS 14.4 – iOS 14.5.1 jailbreak on A12-A14 devices via Fugu14. It was developed by Pwn20wnd for iOS 11 – iOS 14.3 jailbreak. Unc0ver jailbreak is a semi-untethered jailbreak in its nature. But if you have a Fugu14 untether-compatible device, you can untether your unc0ver jailbreak using Fugu 14.

How to install the Fugu14 untether with the unc0ver jailbreak

With unc0ver v7.0.0 you have to set up fugu manually.

But now many bugs have been fixed via Unc0ver v7.0.1, v7.0.2. So, now you can install Fugu14 automatically when unc0ver jailbreak app side-loading via the AltStore v1.4.8.

When you install the Unc0ver via AltStore, it will pop up a message “ jailbreak requires untethering” to make it untether. However, you can select install without untethering if you don’t like.

Get the step by step guide from the Unc0ver Jailbreak page.

Fugu14 with Taurine Jailbreak

Taurine is a semi-untethered jailbreak tool for iOS 14 – iOS 14.3 by CoolStar. The developer hinted about a Taurine upgrade against the Fugu14 release via his discord channel.

However, still Taurine did not upgrade to iOS 14.4 onwards.

Find more details about Taurine from the Taurine jailbreak page.

Fugu Alternatives

Zeon – Zeon is a jailbreak repo extractor. You can install Jailbreak apps using zeon on iOS 14 – iOS 16 running all device models. It is an online process and you can easily install it on your device. You can use it as a Fugu alternative.

Checkra1n Jailbreak – Fugu does not work with iPhone X and older devices. So, you can use Checkra1n as an alternative for these devices running iOS 14 – iOS 14.8.1 jailbreak. Checkra1n also based on the Checkm8 exploit. It is a computer based semi-tethered jailbreak.

Fugu Jailbreak for iOS 13 – iOS 13.5.1

Previously, Linus released fugu Jailbreak for iOS 13 – iOS 13.5.1. Fugu was the first open source jailbreak tool based on the checkm8 exploit two years ago. iPhone 7 is the only officially supported device for that time. That is also in developing mode and only meant to be used by developers.

Important Facts of Fugu (older version)

  • SSH and Substitute automatically install
  • Install Sileo automatically
  • MacOS Application that exploits your iDevice using checkm8 and uploads iStrap, iStrap loader and iDownload
  • It’s need to put your iDevice into DFU mode, run Fugu iStrap, unlock your iDevice and follow the on-screen instructions. Download and install from here.
  • All devices with the A10/A10X CPU should be supported

However, at that time it was not popular because there were a lot of jailbreaks available for these versions. Find iOS 13 – iOS 13.5.1 Jailbreak from here.