CU8 for SDL Trados Studio 2014 SP2 and CU2 for SDL Studio GroupShare has been released, see KB article 5375 and KB article 7246 for more information.
GroupShare Server’s Update is not auto update. So You must download SDLGroupshare2014SP2CU02.zip from kb.sdl.com (KB article 7246). But this update is easy.
Extract the zip file -> Double click exe file -> Install the update according to the navigation.
Cumulative Updates for SDL Trados Studio 2014 SP2 and GroupShare 2014 SP2