Core Insights - Apple has officially stopped signing iOS 18.6.2 and earlier versions, along with iPadOS 18.6.2 and tvOS 18.6, meaning users cannot downgrade back to the iOS 18 series after upgrading to iOS 26 [1] - The iOS 26 official version was released on September 16, featuring a new "Liquid Glass" design language and marking Apple's first unified version number across all platforms [1] - The cessation of support for older versions follows Apple's standard practice of terminating support after the release of new security updates [1] Security and Vulnerability - The Ministry of Industry and Information Technology issued a warning on September 10 regarding a critical vulnerability in iOS 18.6.2 that could lead to unauthorized access, which has already been exploited in cyberattacks [1] - Apple aims to encourage users to adopt the new version that addresses these vulnerabilities, although users can still choose to remain on the iOS 18 series [1] User Guidance - Users upgrading to iOS 26 will lose the option to downgrade, prompting experts to recommend backing up data before upgrading and considering the balance between new features and system compatibility needs [1]

Core Points - Apple has officially launched the iOS 26 system update for iPhone users globally, addressing concerns regarding battery life and device performance [1] Group 1: System Update Details - The update may cause temporary battery drain and device heating, which Apple states is a normal occurrence following major software updates [3] - New features in iOS 26, such as the "liquid glass" dynamic interface and real-time activity components, require background adaptation that may temporarily increase processor load [3] - Users may experience increased power consumption of 15%-20% for devices like the iPhone 14 Pro series during the initial 24 to 48 hours post-update due to adjustments for new computational photography algorithms [3] Group 2: Long-term Effects - Apple warns that the continuous use of certain new features may have long-term impacts on battery health and device performance, depending on user habits and hardware configurations [4] - For instance, enabling real-time activities from third-party apps may lead to an 8%-12% reduction in battery life due to increased background location tracking and data refresh rates [4]