On the night of October 14 2019, the WordPress 5.2.4 update was released to the public.
To update to WordPress 5.2.4, you can do so automatically from Dashboard> Updates menu, or visit https://wordpress.org/download/release-archive/ to download the new version.
From the announcement of the WordPress 5.2.4 release we see that all versions of 5.2 had the following bugs, which were fixed in 5.2.4.
Software updates are also available for versions 5.1 or 3.7 for anyone not using the 5.2 version.
Vulnerabilities that the new version fixes:
Evan Ricafort discovered an XSS (cross-site scripting) problem that could work in Customizer.
JD Grimes discovered and mentioned a method that can be seen in unauthenticated posts.
David Newman discovered a method for poisoning the cache of JSON GET requests via the Vary: Origin header.
Eugene Kolodenker found a server-side request forgery
Ben Bidner from the WordPress Security Team discovered issues with the admin referrer validation.
Those of you who want to upgrade manually, the files that were changed with the update are:
/wp-includes/class-wp.php /wp-includes/class-wp-query.php /wp-includes/functions.php /wp-includes/http.php /wp-includes/pluggable.php / wp-includes /rest-api.php