error: rpmts_HdrFromFdno: Header V3 RSA/SHA1 Signature, key ID XXXXXXXX: BAD
error: rpmdbNextIterator: skipping h# XXXX Header V3 RSA/SHA1 Signature, key ID XXXXXXXX BAD
Solution:
wget http://mirror.centos.org/centos/6/updates/x86_64/Packages/nss-softokn-freebl-3.14.3-19.el6_6.x86_64.rpm
rpm2cpio nss-softokn-freebl-3.14.3-19.el6_6.x86_64.rpm | cpio -idmv
cp ./lib64/libfreeblpriv3.* /lib64
yum update
All good now, back to work everyone.