This maintenance release fixes a severe bug in 4.9.3, which will cause sites that support automatic background updates to fail to update automatically, and will require action from you (or your host) for it to be updated to 4.9.4.
This morning we updated WordPress to 4.9. Highlights include “…an improved Customizer workflow with design drafts, locking, scheduling, and preview links. What’s more, code syntax highlighting and error checking will make for a clean and smooth site building experience. Finally, if all that wasn’t pretty great, we’ve got a great new Gallery widget and improvements to theme browsing and switching.”
This morning we updated WordPress to 4.8.1. From the release news post: “This release contains 29 maintenance fixes and enhancements, chief among them are fixes to the rich Text widget and the introduction of the Custom HTML widget.”