Red Hat has announced
that its longstanding “rhsa-announce” mailing list will be shut down on
October 10. That is the list that receives security advisories for
Red Hat Enterprise Linux and a whole slew of related products. Anybody who
was counting on that list for Red Hat security advisories will need to find
an alternative; a few options are listed in the announcement.

Source: LWN.net – The end of the Red Hat security-announcements list