It is known that the macOS Big Sur 11.5 update is available to all Mac users running Big Sur. The update has a few bug fixes, some important security fixes, and the ability for the Podcasts app to display either all shows or followed shows. The full release notes, which are quite brief, are further below.
Despite being a rather small update in terms of changes, the 11.5 update weighs in around 3GB.
Mac users running Catalina (10.15.7) and Mojave (10.14.6) will find Security Update 2021-004 Catalina and Security Update 2021-005 Mojave available to download and install instead, along with an update to Safari.
And, iPadOS 14.7 and iOS 14.7 are also available for iPad and iPhone.
How to Download & Install MacOS Big Sur 11.5 Update
Be sure to backup the Mac with Time Machine before installing any system software updates.
1.Go to the Apple menu or Dock
2.Choose System Preferences
3.Select the Software Update control panel
4.Choose to update macOS Big Sur 11.5
T4TeCH 
Mike Lee-111 
