download latest Flash (YUM)
install repository:

rpm -ivh adobe-release-x86_64-1.0-1.noarch.rpm

add GPG Key

rpm -import /etc/pki/rpm-gpg/RPM-GPG-KEY-adobe-linux

update repos:

yum repolist
yum check-update

or:

yum update

install Flash:

yum -y install flash-plugin AdobeReader_enu adobe-release-x86_64