If you have an iPhone 6s or later, your phone is compatible with iOS 15 and you must have the latest version, iOS 15.6.1. Likewise, if you have a 5th generation iPad, 4th generation iPad mini, or 4th generation iPad Air, you can run iPadOS 15.6.1.
But those with older iPhones and iPads are stuck on iOS 12, which doesn’t get regular updates. Every so often, however, Apple releases an update for this year-old operating system with critical security fixes. Some security vulnerabilities are so important that getting them out is urgent, even for the few users who still cling to iPhones or iPads from more than six years ago.
Well, iOS 12.5.6 is one such release. It includes a fix for the same critical WebKit vulnerability that was fixed in iOS and iPadOS 15.6.1:
Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
WebKit is the browser engine used by Safari and all other web browsers on iPhone and iPad, and this is a particularly annoying security vulnerability — and one that may have already been exploited in the wild.
So if you have an older iPhone or iPad that is stuck on iOS 12, open the Settings app and go to General > Software update to download iOS 12.5.6 today.