After some time of inactivity, JIRA logs me out. When I log in again, it warns me about a possible cross site request forgery. I use a Mac with OSX 10.11.3, and the most recent version of Safari.
Screen Shot 2016-03-30 at 13.51.21.png
My hunch: I use the iOS tempo app where I am also signed in with a google apps account. I think this might be connected to the issue.