WordPress has released WordPress 4.2 yesterday but some of your WordPress installation should be upgraded to WordPress 4.1.3 today. This was a maintenance release for the recent security update WordPress 4.1.2.
WordPress 4.1.3 has fixed the following database related issue:
Fix database writes for esoteric character sets, broken in the WordPress 4.1.2 security release. Neither UTF-8 nor latin1 were affected.
Following files were revised in this update:
readme.html
wp-admin/about.php
wp-includes/version.php
wp-includes/wp-db.php
For more information, you can refer the following codex URL:
http://codex.wordpress.org/Version_4.1.3
They have also released WordPress 4.2. You should consider upgrading to WordPress 4.2.