CentOS7 not booting after "yum update" mokListRT fails
As noted in the CentOS bug report, this was fixed with the following updates:
mokutil.x86_64 15-2.el7.centos updates
shim-ia32.x86_64 15-2.el7.centos updates
shim-unsigned-ia32.x86_64 15-2.el7.centos updates
shim-unsigned-x64.x86_64 15-2.el7.centos updates
shim-x64.x86_64 15-2.el7.centos updates