Posted by Drupal Security Team on July 17, 2017 at 11:34pm
Symfony contacted the Drupal Security team about today's Symfony security release addressing an issue in UserPasswordValidator. This announcement is to reassure the Drupal community that Drupal 8 is not affected by this fix, as it does not make use of this security component. There is no Drupal 8 release scheduled for this, and there is no action you need to take on your Drupal site(s).