WordPress is a popular open-source content management and blogging system that is available in a hosted model on WordPress.com and as a self-hosted application that users can choose to host wherever they want. WordPress.com also offers the Jetpack plug-in for self-hosted WordPress users, which provides multiple services to help users manage and secure sites.
WordPress is now beginning to disconnect self-hosted sites that have not updated the Jetpack plug-in.
“Last spring, we discovered a vulnerability in Jetpack and have been hard at work helping users update their sites to a secure version,” WordPress wrote in an email sent to affected site administrators. “Your site has been running an old, highly insecure version (1.9.2) of the Jetpack plugin. To keep your site secure, we have disconnected it from WordPress.com.”