WordPress 2.5.1  has been released. It includes a number of bug fixes, performance enhancements, and one very important security fix.
If you are interested in only the security fixes, just replaced the following files.
There are more than 70 bugs and performance fixes in 2.5.1, here is an outline of it:
- Performance improvements for the Dashboard, Write Post, and Edit Comments pages.
- Better performance for those who have many categories
- Media Uploader fixes
- An upgrade to TinyMCE 3.0.7
- Widget Administration fixes
- Various usability improvements
- Layout fixes for IE