We released new versions of Drupal 7 and Drupal 8 yesterday that fixed a highly critical security bug. All software has security bugs, and fortunately for Drupal, critical security bugs are rare. What matters is how you deal with security releases.
I have the utmost respect for how the Drupal Security Team manages a security release like this — from fixing the bug, testing the solution, providing advance notice, coordinating the release, to being available for press inquiries and more.
The amount of effort, care and dedication that the Drupal Security Team invests to keep Drupal secure is unparalleled, and makes Drupal's security best-in-class. Thank you!