Yum update が "[Errno 14] PYCURL ERROR 77 - "Problem with the SSL CA cert (path? access rights?)"" エラーで失敗します

Issue

$ yum list installed kernel*
Loaded plugins: product-id, refresh-packagekit, security, subscription-manager
Not root, certificate-based repositories not updated
Repo rhel-6-workstation-rpms forced skip_if_unavailable=True due to:/etc/rhsm/ca/redhat-uep.pem
Repo rhel-6-workstation-rpms forced skip_if_unavailable=True due to:/etc/pki/entitlement/2615698930652781773-key.pem
Repo rhel-6-workstation-supplementary-rpms forced skip_if_unavailable=True due to:/etc/rhsm/ca/redhat-uep.pem
Repo rhel-6-workstation-supplementary-rpms forced skip_if_unavailable=True due to:/etc/pki/entitlement/2615698930652781773-key.pem
Repo rhel-6-workstation-optional-rpms forced skip_if_unavailable=True due to:/etc/rhsm/ca/redhat-uep.pem
Repo rhel-6-workstation-optional-rpms forced skip_if_unavailable=True due to:/etc/pki/entitlement/2615698930652781773-key.pem
Repo rhel-6-workstation-rhev-agent-rpms forced skip_if_unavailable=True due to:/etc/rhsm/ca/redhat-uep.pem
Repo rhel-6-workstation-rhev-agent-rpms forced skip_if_unavailable=True due to:/etc/pki/entitlement/2615698930652781773-key.pem
elrepo                                                   | 2.6 kB     00:00
https://cdn.redhat.com/content/dist/rhel/workstation/6/6Workstation/x86_64/optional/os/repodata/repomd.xml:[Errno 14] PYCURL ERROR 77 - "Problem with the SSL CA cert (path? access rights?)"
Trying other mirror.
https://cdn.redhat.com/content/dist/rhel/workstation/6/6Workstation/x86_64/rhev-agent/3/os/repodata/repomd.xml:[Errno 14] PYCURL ERROR 77 - "Problem with the SSL CA cert (path? access rights?)"
Trying other mirror.
https://cdn.redhat.com/content/dist/rhel/workstation/6/6Workstation/x86_64/os/repodata/repomd.xml:[Errno 14] PYCURL ERROR 77 - "Problem with the SSL CA cert (path? access rights?)"
Trying other mirror.
https://cdn.redhat.com/content/dist/rhel/workstation/6/6Workstation/x86_64/supplementary/os/repodata/repomd.xml:[Errno 14] PYCURL ERROR 77 - "Problem with the SSL CA cert (path? access rights?)"
Trying other mirror.
Error:No matching Packages to list