MySQL 5.5.39 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://downloads.skysql.com/archive/index/p/mysql/v/5.5.39

This release, similar to the last 5.5 release, is mostly uneventful.

There were two “Functionality Added or Changed” and 24 bugs fixed.

The “Functionality Added or Changed” changes are:

• CMake support was updated to handle CMake version 3.
• The timed_mutexes system variable has no effect and is deprecated.

Out of the 24 bugs, most seemed rather minor or obscure, but here are the ones I think are worth noting (crashing, security, wrong results, deadlock):

• InnoDB: Opening a parent table that has thousands of child tables could result in a long semaphore wait condition.
• …