Security updates for Friday

Security updates have been issued by CentOS (libvirt and python), Debian (intel-microcode, php-horde-form, and znc), Fedora (firefox), Mageia (firefox, flash-player-plugin, git, graphicsmagick, kernel, kernel-linus, kernel-tmb, phpmyadmin, and thunderbird), Oracle (libssh2, libvirt, and python), Red Hat (libvirt and python), Scientific Linux (libvirt), Slackware (bind and mozilla), SUSE (enigmail), and Ubuntu (bind9, intel-microcode, mosquitto, postgresql-10, postgresql-11, and thunderbird).