In WordPress 3.7 and future updates, there is a new automatic background update feature in an effort to promote better security. By default, WordPress only auto updates minor and translation file updates.
However, you can disable or enable any type of WordPress updates by adding one of the following codes to your wp-config.php file (Source WordPress Codex):
To specifically enable development (nightly) updates, use the following:
add_filter( 'allow_dev_auto_core_updates', '__return_true' );
To specifically disable minor updates, use the following:
add_filter( 'allow_minor_auto_core_updates', '__return_false' );
To specifically enable major updates, use the following:
add_filter( 'allow_major_auto_core_updates', '__return_true' );
Plugins, themes and translation file:
Automatic plugin and theme updates are disabled by default.
To enable automatic updates for plugins, use the following:
add_filter( 'auto_update_plugin', '__return_true' );
To enable automatic updates for themes, use the following:
add_filter( 'auto_update_theme', '__return_true' );
Automatic translation file updates are already enabled by default, the same as minor core updates. To disable translation file updates, use the following:
add_filter( 'auto_update_translation', '__return_false' );
Core Updates:
To disable all core-type updates only, use the following:
add_filter( 'auto_update_core', '__return_false' );
All Updates
To completely disable all types of automatic updates, core or otherwise, add the following to your wp-config.php file:
define( 'AUTOMATIC_UPDATER_DISABLED', true );
You can also disable all automatic updates using the following filter:
add_filter( 'automatic_updater_disabled', '__return_true' );