Apple released critical updates, including iOS 26.3.1(a) on March 17, 2026, to fix the CVE-2026-20643 vulnerability in WebKit. This background security patch addresses a flaw that allows bypassing the same-origin policy, protecting devices against targeted attacks. Immediate updating is recommended in Settings > General.

Details of Security Updates (March 2026):

iOS 26.3.1(a) (March 17): First background security improvement ("Rapid Security Response") for iOS 26, aimed at protecting the WebKit engine.

iOS 26.3.1 (March 4): Official update for iPhone 11 and later models, providing security and stability patches.

iOS 15.8.7 and iOS 16.7.15 (March 11): Security patches for older iPhone models that are not compatible with iOS 26.

iOS 18.7.6 (Early March): Planned release for devices compatible with iOS 18 such as iPhone XS, XS Max, and XR.