As well as the new iOS 14.8 update for the iPhone and iPadOS 14.8 for the iPad, Apple has also released a new software update for the Mac, macOS Big Sur 11.6 .
The macOS Big Sur 11.6 does not comes with any new features, this update is a security update and it deals with the same security issues as iOS 14.8.
Here are the details on what security issues have been fixed:
macOS Big Sur 11.6
Released September 13, 2021
CoreGraphics
Available for: macOS Big Sur
Impact: Processing a maliciously crafted PDF may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
Description: An integer overflow was addressed with improved input validation.
CVE-2021-30860: The Citizen Lab
WebKit
Available for: macOS Big Sur
Impact: Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
Description: A use after free issue was addressed with improved memory management.
CVE-2021-30858: an anonymous researcher
As with the iOS 14.8 and iPadOS 14.8 software updates, it is recommended that you install this software update on your Mac. The macOS Big Sur 11.6 update should be the last update for macOS Big Sur ahead of the release of the new macOS 12 Monterey software update.
Source Apple