Apple has released a security update for OS X Yosemite 10.10.2.

Apple did not specify the content update, saying only that it is recommended for all users, and improves OS X security. You can download Security Update 2015-003 from the Updates section of the Mac App Store, or as a separate download from their support site. Apple should post more about the update in this support article shortly.

Source: Apple (1), (2)