The iOS 18.6 has recently launched. iOS 18.5 will no longer be signed by Apple, meaning that people who have updated their iOS to the latest version 18.6 will not be able to downgrade back to iOS 18.5.
Apple does this usually around one week after a new software update launches to make sure that iPhone users are up to date with the security improvements made to their iPhone. This is done through a server side verification check called signing where updates are not installed until they pass the verification tests to prevent them from being susceptible to threats and attacks.

This protects the users from downloading any outdated patches of the iOS that don’t have these up to date security changes made. The iOS 18.6 update was made emphasizing on updates in securities dealing with over 20 vulnerabilities that were found in the last software version.













