After Pangu released iOS 9.3.3 jailbreak it was inevitable that Apple would patch it but today Apple surprised everyone by releasing another iOS 9 update making the latest iOS 9.3.5. 

The reason behind the release was due to a serious security hole that has been exploited by an Isreali hacking firm the “NSO Group”

The NSO Group had developed software that could read emails, text messages and record sounds, collect passwords, trace the whereabouts of the phone user, access calls and contacts. 

Apple hasn’t disclosed if the exploits were specific to the iPhone, or other smartphone models, but called this “an important security update” recommended for all users.

More info on the hack can be found here