Joomla.org recently released an update to Joomla 2.5. This is a security update and covers a few discovered bugs and exploits from version 2.5.6.
We recommend you upgrade immdiately!
If we are managing your site, it will be automatically updated. Else you can update it yourself.
Read the full release here. http://www.joomla.org/announcements/release-news/5463-joomla-2-5-7-released.html