WordPress 6.9.3 is a quick bugfix for an issue that was broke in the WordPress 6.9.2 security update.

You can read more by looking at the release notes: https://wordpress.org/documentation/wordpress-version/version-6.9.3/

You can also read more about the 6.9.2 release here: https://wordpress.org/documentation/wordpress-version/version-6-9-2/

You can also see a complete list of changes: https://core.trac.wordpress.org/query?status=closed&milestone=6.9.3&col=id&col=summary&col=owner&col=type&col=priority&col=milestone&col=component&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.