Been a long time since ive seen news of IOS jailbreaks but Houdini is back on the scene:

He seems to have found an exploit that works on (all?) iOS devices that are on iOS 11.1.2 or lower. The exploit allows code to be run with kernel privilages so it has the highest privilages possible. Ian Beer plans to release his work on the tfp0 (task at pid 0) exploit which according to Redditors is about 80% of a jailbreak. This means that with some work from other people, a full jailbreak on iOS 11.1.2 may land soon! Just donít update to iOS 11.2 if you want a jailbreak, if youíre on 11.2, you may downgrade without restoring by reading the instructions in the link below!

iOS 10.3.3 (included) and lower exploit by Siguza

Siguza, who had a huge part in getting us Phoenix (iOS 9.3.5 jailbreak for A5/A6 devices) has released his work on the v0rtex exploit.

His current work gets code to run with root permisisons on all versions of iOS lower than 10.3.3 (included). Apparently, this exploit only works on A7-A9 devices but with some work, it could be made to work on 32-bit (Apple A6) devices too. According to some Redditors, this can be considered as 60% of a jailbreak because more work needs to be done (such as tfp0) but thereís still hope.