No and nein.. yum –security check-update/update does NOT work in CentOS. This is simply because the CentOS is missing this metadata. When you are using RHEL you pay for this metadata. This is not entirely obvious at first glance, but I guess they didn’t want to alter the source code for yum, which still provides –security parameter for CentOS.
If you want automatically flagged packages, buy RHEL license and use RHEL instead…or if you are a dev, use the free developer program.
Otherwise, use https://cefs.steve-meier.de/
Sadly his parser is not open source so you need to rely on this guy. He hasn’t failed this far though.