In conjunction with an iOS update, Apple has also released a supplemental update to macOS Catalina, eradicating a bug that was forcing iCloud logins for some users dozens of times a day.
Apple says that beyond the iCloud Login update, the update will improve installation reliability on computers with low available space, rectifies a Setup Assistant completion problem that was forcing users to restart their machine during the initial login, resolves an iCloud Terms and Conditions acceptance issue, and improves the reliability of iCloud saves of Apple Arcade data.
It does not appear that there are any security updates at all in the update.
Following months of beta testing, Apple's macOS Catalina was released on October 7. Among the most notable changes are Sidecar allowing an iPad to be used as a second screen, the split of iTunes into several applications, and the death of 32-bit applications.