WordPress 2.8.6 has been released for security updates. The major changes are to fix two security problems that can be exploited by registered, logged in users who have posting privileges. So make sure you upgrade your WordPress as soon as possible.
Read more: WordPress 2.8.6 Security Release
Download: WordPress 2.8.6
Why so many security patches lately? I updated 4 versions from 2.8.2 to 2.8.6 in such a short time.