iOS 26 won’t let you downgrade, as Apple stops signing iOS 18.6.2
Apple has stopped signing iOS 18.6.2, which means users who upgraded to iOS 26 can no longer go back.
iOS 26 was officially released on September 15 for iPhone 11 through iPhone 17 models, as well as the iPhone SE. Now, Apple has stopped signing its previous update, iOS 18.6.2, making it impossible to downgrade to it or from iOS 26, for that matter.
At this time, iOS 26.0 is the only signed version of iOS available for iPhones capable of running iOS 26. Apple did release an iOS 18.7 update, but this was rolled out as an OTA-only update for iOS 26-supported devices, which means there are no IPSW files available. This leaves users with no way to roll back to any version of iOS 18 after upgrading to iOS 26.
Apple digitally signs firmware updates to ensure they are legitimate, unmodified, and approved for installation on specific devices. Once an iOS or iPadOS update is no longer signed, it cannot be installed, which can prevent users from reverting to older, potentially less secure versions.
In this case, iPhone users running older iOS 18 versions can only upgrade to iOS 26, with no option to downgrade afterward. Fortunately, users can continue running iOS 18.6.2 for as long as they want, although they may miss out on important security updates or run into app compatibility issues.
Alongside iOS 18.6.2, Apple has stopped signing iPadOS 18.6.2 and tvOS 18.6.
