Open source and widely popular CMS Drupal released a maintenance fix to their 8.x branch a little under a week ago. This release fixes some bugs in the branch, but there’s no security fixes as part of it. The list of changes is available here. The change log also lists April 20th as the release date for Drupal 8.1.0 which should have further fixes and new features.
For those people running a CMS site, keeping up to date with the security and bug fix patches is good practice, and therefore you should look to update as soon as possible.