Apple releases macOS Catalina 10.15.5 supplemental update with important security fixes

Apple is releasing new software today, starting with iOS, iPadOS, and watchOS, but Apple isn’t leaving macOS Catalina out of the mix entirely.

On Monday, Apple released the latest supplemental update for macOS Catalina 10.15.5. The update is minor in scale, but it does include important security updates. As is par for the course, the update is free for macOS users. If you have automatic updates switched on, the new software will be downloaded and installed without your direct input.

However, if you want to update manually, simply open System Preferences –> Software Update and follow the onscreen instructions to get the latest version of Apple’s desktop operating system installed. It’s worth noting that macOS High Sierra users also have an update available for them as well.

Apple suggests in the changelog for the supplemental update to macOS Catalina 10.15.5 that all users should install it as soon as possible. Here’s that changelog:

macOS Catalina 10.15.5 Supplemental Update

macOS Catalina 10.15.5 supplemental update provides important security updates and is recommended for all users.

Some features may not be available for all regions, or on all Apple devices. For detailed information about the security content of this update, please visit:

Just like it did with iOS 13.5.1 and iPadOS 13.5.1, Apple has updated the official security page to reflect the latest software update, which it details as such:


Available for: macOS High Sierra 10.13.6, macOS Catalina 10.15.5

Impact: An application may be able to execute arbitrary code with kernel privileges

Description: A memory consumption issue was addressed with improved memory handling.

CVE-2020-9859: unc0ver

Apple patched this vulnerability in iOS 13.5.1, iPadOS 13.5.1, and tvOS 13.4.6 today, so it makes sense the company is patching it in macOS Catalina as well.

The new software is available now.