Drupal was officially accepted to participate in Google Summer of Code 2019. If you are interested in participating as a mentor or student check out this post.
"This Public Service Announcement is a follow-up to SA-CORE-2019-003. This is not an announcement of a new vulnerability. If you have not updated your site as described in SA-CORE-2019-003 you should do that now."
"Drupal Steward will offer sites a form of mitigation through the implementation of web application firewall rules to prevent mass exploitation of some highly critical vulnerabilities ..."
"Some field types do not properly sanitize data from non-form sources. This can lead to arbitrary PHP code execution in some cases." Please read the full page on this and determine if you need to update your site immediately.