A Chinese researcher has revealed details of critical vulnerabilities in Apple Safari web browser and iOS that could allow a remote attacker to jailbreak and compromise victims’ iPhoneX running iOS 12.1.2 and before versions. The exploit takes advantage of two security vulnerabilities that were first demonstrated at TianfuCup hacking contest held in November last year and then reported to Apple security team. The researcher has chosen not to publish the code for iOS jailbreak in an attempt to prevent malicious attacks against Apple users.
Source: https://thehackernews.com/2019/01/ios12-jailbreak-exploit.html