Please upgrade mosquitto in F20 (and rawhide) to the current version 1.3.1. F20 is now at 1.2.3 and rawhide is at 1.3.
mosquitto-1.3.1-1.fc20 has been submitted as an update for Fedora 20. https://admin.fedoraproject.org/updates/mosquitto-1.3.1-1.fc20
Package mosquitto-1.3.1-1.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 mosquitto-1.3.1-1.fc20' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2014-6994/mosquitto-1.3.1-1.fc20 then log in and leave karma (feedback).
mosquitto-1.3.1-1.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.