A new update for XOOPS (http://xoops.org) has  been released - XOOPS 2.5.1. According to the release article on XOOPS.org -

Several bugs have been fixed as well as security enhancement based on Aung Khant's report.

Please be aware that the bugfix is not complete and 2.5 series will be following small but frequent release rule so that users can take advantage of quick fixes.

There also have been some security reports about the XOOPS 2.5.x series, but the developers have assured the community they are properly addressed.