Moodle 1.9.7 and Moodle 1.8.11 were recently released. Apart from a range of bug fixes and small improvements, ten security vulnerabilities (2 critical, 6 major and 2 minor) have been discovered and fixed since Moodle 1.9.6. (Thanks as usual to the reporters and to all the guys responsible for fixing these serious issues).
WE RECOMMEND ALL MOODLE SITES UPGRADE THEIR SITES TO ONE OF THESE VERSIONS AS SOON AS POSSIBLE.
As per our usual procedure, all 45,000 admins of registered Moodle sites were already privately notified over a week ago.
More details can be found in the Moodle 1.9.7 release notes and the Moodle 1.8.11 release notes. Please read these closely as there may be some changes that affect how you use Moodle.
The releases themselves are available, as always, from our downloads page or any of our CVS mirrors.