Security updates for Tuesday

Security updates have been issued by Debian (cacti and libxslt), Fedora (pcsc-lite and samba), Gentoo (gnutls, phpmyadmin, and tiff), openSUSE (apache2, clamav, dovecot23, nodejs10, SDL, and webkit2gtk3), Red Hat (mod_auth_mellon and rh-python36-python), SUSE (firefox, nspr, nss and python), and Ubuntu (libxslt and webkit2gtk).