The WordPress project has just released a new version due to a security release. WordPress version 4.3.1 fixes important security issues, as a cross-site scripting vulnerability when processing shortcode tags and another one in the user list table. It also includes a patch for an issue that let users without proper permissions publish private posts and make them sticky.
The WordPress team strongly encourages their users to update their site to this version. For more details please check the official announcement. If you already have a running version of Bitnami WordPress, the application will be automatically updated. You can confirm that the update has been done by checking the version from your admin panel.