Joomla! 2.5.27 is now available, this is a security release for the 2.5 series of Joomla! This is a security release addressing issues with yesterday’s 2.5.26 release. This release addresses an issue related to the core update component. This release is considered a security release since it includes two resolved security issues associated with 2.5.26.
Because of the issue with the update component, users who are running 2.5.26 will be unable to update to 2.5.27 using Joomla's update component. click here for full release information.