In WordPress 3.7, there’s a new and interesting feature which allow your blog to automatically upgrade when a new version is available. I think it’s really cool, but if you don’t like it for some reason, here’s a quick recipe to turn it off.
To disable automatic updates, open your wp-config.php file and paste the following line in it:
define( 'AUTOMATIC_UPDATER_DISABLED', true );
Once you saved the file, automatic updates will be turned off and you’ll have to manually upgrade your blog again.