WordPress 6.4.2 is now available and contains fixes for seven bug fixes in core as well as one security fix.
You can read more by looking at the release notes: https://wordpress.org/news/2023/12/wordpress-6-4-2-maintenance-security-release/
You can also see a complete list of changes: https://core.trac.wordpress.org/query?status=closed&resolution=fixed&milestone=6.4.2&order=priority
If you have not done so already – download the update or simply use your existing installation of WordPress to update your site. Either way – this is an excellent time to make a backup copy of your site(s) before upgrading.