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.
WordPress 3.9.2 also contains other security changes:
Download WordPress 3.9.2 or venture over to Dashboard → Updates and simply click “Update Now”.
Sites that support automatic background updates will be updated to WordPress 3.9.2 within 12 hours. (If you are still on WordPress 3.8.3 or 3.7.3, you will also be updated to 3.8.4 or 3.7.4. We don’t support older versions, so please update to 3.9.2 for the latest and greatest.)