Pwn20wnd has done an incredible job and has successfully developed a reliable jailbreak for A8X on A11-based iPhones and iPads running iOS 12 through 12.1.2. So, if you have not updated to the latest version since installing iOS 12 for the first time, you may be able to jailbreak your device now.
For the Unknown, Jailbreak means that restrictions on iOS will be unlocked to gain access to apps from Apple. That way, you can completely redesign the interface and features of your iPhone using the Cydia app (or even Sileo). And while the list of available tweaks continues to shrink due to the difficult jailbreak, a steady stream of compatible tweaks is constantly being leaked by the passionate developers and keeping the community alive.
That is, the latest Unc0ver jailbreaking method currently works works for iOS devices with A8X to A1
1 processors. For iPhones, this ranges from the iPhone 6 S to the iPhone X. The process is fairly straightforward, but since is half untied you will need Activate again by following the same steps every time you restart or shut down your iPhone.
Before jailbreaking your device, it is important to know that Unc0ver only works on devices with A8X on A11, which means that only the following iPhones are covered by this method: [19659007iPhone
Apart from that, you must also remember that Unc0ver will not work if you are not working. I recently updated your iOS device to 12.1.3 or 12.1.4. If you were lucky enough to get down to 12.1.2 before Apple closed the window or have a firmware version between 12 and 12.1.2 installed, you can continue below.
Step 1: Downloading and Installing UncOver  There are several ways to install the Unc0ver tool on your iPhone to jailbreak it. The first method is ideal, but Apple could cause problems in the future. The second method is better, except that you must repeat the process unless you have a paid developer account.
Method 1: Open TweakBox and Install UncOver in Safari
Open Safari on your device to get the ball rolling and visit next.tweakboxapp.com. If you're inside the site, go to the Apps tab by either tapping the top of the Apps tab or swiping to the left. Select once the "Tweakbox App". Scroll down from there and select unc0ver jailbreak to open that page.