Drupal.org has released version Drupal 8.5.6. This release is classified as a security release for all previous versions of Drupal.[1] Pantheon has made the update available for one-click update in site dashboards, and has applied platform mitigations to prevent exploits of this vulnerability. We urge all users to update all environments as soon as possible. Instructions for applying core updates can be found in our Support Center.[2]