This Wednesday, April 25, we will apply a security update to two Drupal 8 sites shortly after it is released. This will occur between 12:00 and 3:00pm EDT, which is 9:00am-12:00pm PDT. The Drupal project has posted a pre-release announcement of this update.
We do not anticipate any service interruption while the update is applied. Still, we advise you to have saved work in the sites prior to the scheduled update. We will post an announcement here when the update has been successfully applied, which will contain more information about the issue.
These are the sites affected: