Fedora 24 has reached yesterday its end of life. No further updates will be available for Fedora 24.

No further updates, including security updates, will be available for Fedora 24. A previous reminder was sent on 21st of July 2017 [0]. Fedora 25 will continue to receive updates until approximately one month after the release of Fedora 27. The maintenance schedule of Fedora releases is documented on the Fedora Project wiki [1]. The Fedora Project wiki also contains instructions [2] on how to upgrade from a previous release of Fedora to a version receiving updates. Mohan Boddu.

https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/DNMTG4GZJRH6E3WLBNWVPUPGLESLOKBN/
https://fedoraproject.org/wiki/Fedora_Release_Life_Cycle#Maintenance_Schedule
https://fedoraproject.org/wiki/Upgrading?rd=DistributionUpgrades