As of this Tuesday, 6th January 2015 there will be no more updates provided for Fedora 19 (aka End Of Life). This includes all security, bugfix and enhancement updates, so it is highly recommended to upgrade your Fedora installations to one of the versions of Fedora that the Fedora Community is still providing updates for (Fedora 20 or Fedora 21)
Older Fedora releases are put into End of Life (EOL) one month after the release of Release X+2. For example, going forward, Fedora 20 will be maintained until 1 month after the release of Fedora 22. and Fedora 21 will be maintained until 1 month after the release of Fedora 23. Check out the Fedora Wiki for further information on retired releases and the Fedora release life cycle.