Macos Big Sur 11.5.1 (20g80) May 2026

: Addresses a serious vulnerability in the IOMobileFrameBuffer .

Released on July 26, 2021, is a maintenance update primarily focused on a critical security patch. Key Update Details macOS Big Sur 11.5.1 (20G80)

While 11.5.1 was security-focused, it carries over the bug fixes introduced in 11.5 (20G71), including: macOS Big Sur 11.5.1 (20G80)

: Users typically install this by going to System Preferences > Software Update . macOS Big Sur 11.5.1 (20G80)

: Despite being a single-patch update, the download size was approximately 2.2 GB for Intel Macs and over 3.1 GB for M1 Macs . Improvements from the 11.5 Branch