Security updates for Wednesday

Security updates have been issued by Arch Linux (calibre, dovecot, and postgresql), CentOS (dhcp and mailman), Fedora (freetype, kernel, leptonica, mariadb, mingw-leptonica, net-snmp, nx-libs, util-linux, wavpack, x2goserver, and zsh), Gentoo (chromium), Oracle (389-ds-base, mailman, and qemu-kvm), Red Hat (389-ds-base, kernel, kernel-alt, libreoffice, mailman, and qemu-kvm), Scientific Linux (mailman), Slackware (firefox and samba), and Ubuntu (samba).