Moodle 2.3.3, 2.2.6 and 2.1.9 are available via the usual open download channels (http://download.moodle.org, CVS or Git).
In addition to a number of bug fixes and small improvements, security vulnerabilities have been discovered and fixed. As always, we recommend that you upgrade your sites to these latest versions as soon as possible. All admins of registered Moodle sites have been notified with security issue details.
See on moodle.org