Fedora currently has 4.6.1
http://sourceforge.net/p/fb-contrib/news/
findbugs-contrib-5.2.0-1.fc20 has been submitted as an update for Fedora 20. https://admin.fedoraproject.org/updates/findbugs-contrib-5.2.0-1.fc20
Package findbugs-contrib-5.2.0-1.fc20: * should fix your issue, * was pushed to the Fedora 20 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing findbugs-contrib-5.2.0-1.fc20' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2014-6566/findbugs-contrib-5.2.0-1.fc20 then log in and leave karma (feedback).
findbugs-contrib-5.2.0-1.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.