Macos Big Sur 11.5.1 (20g80) May 2026

: This was a "surprise" security patch released just five days after version 11.5.

: Addresses a serious vulnerability in the IOMobileFrameBuffer .

: Resolved an issue where smart cards might not work correctly when logging into M1-based Macs. Installation & Compatibility macOS Big Sur 11.5.1 (20G80)

: This security fix was released simultaneously with iOS 14.7.1 and iPadOS 14.7.1 to address the same vulnerability. macOS 11.5.1 - Apple Wiki | Fandom

Released on July 26, 2021, is a maintenance update primarily focused on a critical security patch. Key Update Details : This was a "surprise" security patch released

: Fixed an issue where the play count or last played date might not update in the library.

: An application could potentially execute arbitrary code with kernel privileges. Installation & Compatibility : This security fix was

: Users typically install this by going to System Preferences > Software Update .