WordPress 3.9.2 is released to address some security issues.
WordPress 3.9.2 is now available as a security release for all previous versions. We strongly encourage you to update your sites immediately.
This release fixes a possible denial of service issue in PHP’s XML processing, reported by Nir Goldshlager of the Salesforce.com Product Security Team. It was fixed by Michael Adams and Andrew Nacin of the WordPress security team and David Rothstein of the Drupal security team. This is the first time our two projects have coordinated joint security releases.
It is highly imperative to update to WordPress 3.9.2.