Apple has provided iOS 15.7.1 and iPadOS 15.7.1 with security updates and patches for devices that can't update to iOS 16, or for those who don't want to.
iOS 15.7.1 is available for older iPhones
The new update for users still on iOS 15 and iPadOS 15 addresses similar bugs and security patches available in the recent iOS 16.1 and macOS Ventura releases. The security patch notes list 17 different systems affected by security issues that have been patched.
Anyone capable of updating to iOS 15.7.1 or iPadOS 15.7.1 should do so as soon as is reasonable. The update addresses known security issues that could put the user at risk.
The following systems were addressed via this update: Apple Neural Engine, Audio, Backup, FaceTime, Graphics Driver, Image Processing, Kernel, Model I/O, ppp, Safari, WebKit, WiFi, and zlib.
Apple listed the following devices that the update is designated for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation).
Learn about the patches and view the CVE numbers via Apple's support page for the update.
Support for the iPhone 6s, iPhone 7, and iPod touch was dropped in iOS 16. The Pad Air 2 and iPad mini 4 don't support iPadOS 16.
Those with automatic updates enabled won't have to do anything -- the update will likely install overnight. Those who would like to install the update manually can do so via the Settings app. Just select "General" then "Software Update."