Automatic background updates were introduced in WordPress 3.7 in an effort to promote better security, and to streamline the update experience overall. By default, only minor releases – such as for maintenance and security purposes – and translation file updates are enabled on most sites. In special cases, plugins and themes may be updated.
Whether you are like me, would like to control upgrade actions on your WordPress website or if you are in a production environment and don’t want your website to be upgraded without previous testing… This is how you should do to prevent WordPress.
Edit your wp-config.php file that is located in the base folder of your WordPress installation, and insert the following lines:
/**# disabling WP automatic updates for WP 3.7+ */
define( 'WP_AUTO_UPDATE_CORE', false );
You may find more details on how to control updates of your WordPress website here.