Seems to have returned. Looks like sl-security repo. repodata/updateinfo.xml.bz2 timestamp goes from 1472831996 to 1472837835.89. Looks like the floating point issue. Some tool is writing bad timestamps. /etc/cron.daily/0yum-daily.cron: Not using downloaded repomd.xml because it is older than what we have: Current : Fri Sep 2 09:59:56 2016 Downloaded: Fri Sep 2 09:59:55 2016