Verified in rhevm-3.3.1-0.47.el6ev.noarch (is34).
Verified by automation (using Selenium).
I spun up 4 Firefox browsers in parallel and each one performed login & logout on User Portal 20 times in a row.
All login/logout actions eneded up well, no problems were encountered.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.