Ian Beer, a security researcher for Google, as a part of their Project Zero division, best known for his efforts in the iOS 10.1 jailbreak, has released more exploits that could be beneficial to the jailbreak community once again. These exploits have been released in a userspace research tool known as "triple_fetch" for other security researchers to work with and expand upon the work that Beer has already completed. Bear in mind that these exploits are only for the userspace component of iOS, which is the portion of memory where user processes, such as apps, run. So this is not a complete jailbreak, but rather a great start for other developers to continue from.
It provides two exploits, those being sandbox escape, and privilege escalation. The first kind allows you to break out of the "sandbox" an app is contained in and see the rest of the files and contents of the device, such as system files and contents of other apps. The second exploit means that we now have root access and can write to the filesystem, this is a big head start but is not the complete picture. We still need more access have a complete jailbreak, as read/write for the filesystem, while powerful, is not enough.
These exploits supposedly work up to iOS 10.3 and give us a bigger chance at having a jailbreak than ever before for that firmware. Hopefully, someone will come along and complete the work that Ian Beer has started, just like someone did with the Yalu1011 jailbreak, which we mind you, was based on top of Ian Beer's exploits.