Apple stopped signing iOS 14.7.1 codes on Monday, ending the downgrade from iOS 14.8 and the recently released iOS 15.
Apple released iOS 14.7.1 in late July as a patchFixed an issue where the Apple Watch could not be unlocked by an iPhone with Touch ID.
The patch also fixed a security hole that allowed an attacker to execute arbitrary code with kernel privileges. The security flaw was reportedly used in zero-click attacks deployed in NSO Group's Pegasus hacking tool.
After a new iOS is released, Apple typically stops signing off on traditional code to protect customers from nefarious practices trying to exploit newly discovered vulnerabilities. Preventing users from downloading old code also allows Apple to make more iOS devices use the latest, feature-rich software.
Apple has officially released iOS 15, with new improvements and user interface changes. New features include live text and visual queries, focus, updated Apple Maps, health App updates, iCloud+ integration, Safari browser redesign and more.
Apple said earlier this year that it would not automatically push iOS 15 to users for a variety of reasons, noting that it would continue to provide security updates for iOS 14 after the new operating system was introduced. Users who are still using iOS 14 will see a choice of two software updates in their Settings, one for the latest version of iOS 14 with bug fixes and the other for iOS 15.