This is a critical security update and for this database version (db_version in wp_options) has remained at 15477.
- Fix XSS vulnerabilities in the KSES library: Don’t be case sensitive to attribute names. Handle padded entities when checking for bad protocols. Normalize entities before checking for bad protocols in esc_url().
List of Files Revised
Get the latest update here if you prefer to manually update or else just click the automatic update button in your admin panel.