In Patrick Volkerding’s absence, due to his health, a number of Slackware users started slacksec.org to keep up with security concerns. I set up a local mirror of the slacksec packages and they are available via http and ftp:
http://ftp.pbandjelly.org/pub/slacksec/
ftp://ftp.pbandjelly.org/pub/slacksec/
(links removed – no longer available)