iOS 15.8.2 and iPadOS 15.8.2 updates have been released by Apple and are now available for download on older models of iPhone and iPad.
If you have older iPhones that include iPhone 7, iPhone 7 Plus, iPhone SE, iPhone 6s, iPhone 6s Plus, and iPod touch 7th generation then you can download iOS 15.8.2 right now.
Similarly, those who own an iPad mini 4 and iPad Air 2 can download iPadOS 15.8.2 update on their devices. Both of these updates are available for download over the air via Settings -> General -> Software Update.
You also have the option to download iOS 15.8.2 IPSW and iPadOS 15.8.2 IPSW, and then use iTunes on Windows and Finder on Mac to manually install these updates.