Apple pushed out iOS 15.7.1 and iPadOS 15.7.1 updates (internal version number: 19H117) for iPhone and iPad users, 45 days after the last release.
Note that due to server configuration caching issues at Apple’s regional nodes, there may be a slight delay in detecting the update in some places, usually within half an hour, not too long.
The iOS and iPadOS 15.7.1 update can be downloaded to eligible iPhones and iPads through Settings – General – Software Update. This update is designed for older iPhones and iPads that are unable to run iOS 16 and iPadOS 16, and is also available to those who currently choose not to update to iOS 16.
The iOS 15.7.1 release was delayed because Face ID did not work on some iPhones during Beta testing, and Apple may have fixed related issues before releasing the update.
According to Apple’s update notes, iOS 15.7.1 includes important security fixes that are recommended for all users. iOS 15.7.1 fixes a number of vulnerabilities, including a kernel vulnerability that Apple says may have been exploited, so all users should update as soon as possible. iOS 16 users received these fixes in the iOS 16.1 update.