Get it while it's hot! :hah:
This is a security release so it is best to upgrade as soon as you can. You can read about it here:
http://www.simplemachines.org/community/index.php?topic=509417.0 (http://www.simplemachines.org/community/index.php?topic=509417.0)
The support topic is here:
http://www.simplemachines.org/community/index.php?board=147.0 (http://www.simplemachines.org/community/index.php?board=147.0)