CentOS

snapd packages need update:
---> Package snap-confine.x86_64 0:2.45.3.1-1.el7 will be updated
---> Package snap-confine.x86_64 0:2.47.1-1.el7 will be an update
---> Package snapd.x86_64 0:2.45.3.1-1.el7 will be updated
---> Package snapd.x86_64 0:2.47.1-1.el7 will be an update
---> Package snapd-selinux.noarch 0:2.45.3.1-1.el7 will be updated
---> Package snapd-selinux.noarch 0:2.47.1-1.el7 will be an update

error:
Error: Package: snapd-selinux-2.47.1-1.el7.noarch (epel)
Requires: selinux-policy-base >= 3.13.1-268.el7
Installed: selinux-policy-targeted-3.13.1-266.el7_8.1.noarch (@updates)
selinux-policy-base = 3.13.1-266.el7_8.1
Available: selinux-policy-minimum-3.13.1-266.el7.noarch (base)
selinux-policy-base = 3.13.1-266.el7
Available: selinux-policy-minimum-3.13.1-266.el7_8.1.noarch (updates)
selinux-policy-base = 3.13.1-266.el7_8.1
Available: selinux-policy-mls-3.13.1-266.el7.noarch (base)
selinux-policy-base = 3.13.1-266.el7
Available: selinux-policy-mls-3.13.1-266.el7_8.1.noarch (updates)
selinux-policy-base = 3.13.1-266.el7_8.1
Available: selinux-policy-targeted-3.13.1-266.el7.noarch (base)
selinux-policy-base = 3.13.1-266.el7

my selinux-policy-base version:
Package selinux-policy-targeted-3.13.1-266.el7_8.1.noarch already installed and latest version

Looks like selinux-policy-targeted-3.13.1-268 is part
of CentOS 7.9, which isn't released yet. You can get
it by enabling the CR repo.

thanks. I will wait for official release.

The official release will be no different to CR, it's just that you can have CR now rather than waiting.

yum --enablerepo=cr update