Security updates for Monday

Security updates have been issued by Debian (c-ares, gnutls28, golang-github-opencontainers-selinux, isc-dhcp, nss, openssl, snort, and thunderbird), Fedora (clamav, curl, phpMyAdmin, thunderbird, vim, webkitgtk, and xen), Red Hat (firefox), Slackware (kernel), SUSE (apache2-mod_security2, gssntlmssp, postgresql-jdbc, postgresql12, and timescaledb), and Ubuntu (firefox).