苹果终止对旧版iOS 18的广泛支持，数亿iPhone用户需立即升级至iOS 26

Core Viewpoint - Apple will end security updates for the iOS 18 series on most devices by December 2025, requiring millions of iPhone users to upgrade to iOS 26 for security and functionality [1][2]. Group 1: Software Support Changes - Starting December 12, 2025, only iPhone XS, XS Max, and XR will receive security patch support for iOS 18.7.3, while all other compatible devices must upgrade to iOS 26 for updates [2]. - This decision marks a significant reduction in the maintenance window for older operating systems, contrasting with Apple's previous practice of providing parallel security updates for several months after a new system release [2]. Group 2: Compatibility and Security - Devices compatible with iOS 26 include iPhone 11 series, iPhone 12 to 16 series, second and third generation iPhone SE, and the newly released iPhone 16e. Upcoming iPhone 17 series and rumored iPhone Air will also ship with iOS 26 [2]. - The iOS 26.2 update includes critical security fixes, making it risky to remain on iOS 18 [2]. Group 3: New Features in iOS 26 - iOS 26 introduces several innovative features, including AI-driven call screening, a smart queue assistant, and a "Liquid Glass" visual design for the lock screen [3]. - Enhancements in the camera and photo applications, along with improved cross-platform compatibility, are also part of iOS 26 [3]. - Upcoming updates, such as iOS 26.3, will simplify data migration between iOS and Android devices, while iOS 26.4 is expected to bring significant upgrades to Siri [3]. Group 4: User Feedback and Recommendations - User concerns regarding interface adaptability, particularly from visually impaired individuals, have been alleviated with ongoing optimizations in iOS 26.2 [4]. - Experts recommend that eligible users promptly update their systems due to the accumulating risks of security vulnerabilities [4].