On August 4, 2015, WordPress 4.2.4 was released to the public. This is a security update for all previous WordPress versions.
To download WordPress 4.2.4, update automatically from the Dashboard > Updates menu in your site's admin area or visit https://wordpress.org/download/release-archive/.
For step-by-step instructions on installing and updating WordPress:
If you are new to WordPress, we recommend that you begin with the following:
From the announcement post, WordPress 4.2.4 fixes three cross-site scripting vulnerabilities and a potential SQL injection that could be used to compromise a site (CVE-2015-2213).
It also includes a fix for a potential timing side-channel attack and prevents an attacker from locking a post from being edited.
In addition to the security fixes, WordPress 4.2.4 contains fixes for 4 bugs from 4.2.3, including:
readme.html wp-admin/about.php wp-admin/includes/class-wp-upgrader.php wp-admin/includes/post.php wp-admin/includes/update-core.php wp-admin/js/nav-menu.js wp-admin/js/nav-menu.min.js wp-admin/post.php wp-includes/class-wp-customize-widgets.php wp-includes/class-wp-embed.php wp-includes/default-widgets.php wp-includes/formatting.php wp-includes/l10n.php wp-includes/post.php wp-includes/shortcodes.php wp-includes/theme.php wp-includes/version.php wp-includes/wp-db.php