Since the beginning of December, Apple has been pushing iPhone users who opted to stay on iOS 18 to install iOS 26 instead. Apple started by making the iOS 18 upgrades less visible, and has now transitioned to making new iOS 18 updates unavailable on any device capable of running iOS 26. If you have an iPhone 11 or later, Apple is no longer offering new versions of iOS 18, even though there was a security update that came out alongside iOS 26.2.