Arch: https://wiki.archlinux.org/index.php/Security

CentOS: https://wiki.centos.org/HowTos/OS_Protection (limited)

Debian: https://www.debian.org/doc/manuals/securing-debian-howto/ind... (old)

Fedora: https://docs.fedoraproject.org/en-US/Fedora/19/html/Security... (old)

Mageia: https://wiki.mageia.org/en/Msec (limited)

Oracle Linux: https://docs.oracle.com/cd/E52668_01/E54670/html/index.html

Red Hat: https://access.redhat.com/documentation/en-us/red_hat_enterp...

Slackware: https://docs.slackware.com/howtos:security:start (limited)

SuSE: https://www.suse.com/documentation/sles-15/singlehtml/book_h...

Ubuntu: https://help.ubuntu.com/lts/serverguide/security.html.en (limited)