A shim security update has been released for CentOS 7.

CentOS-announce: CESA-2020:3217 Moderate CentOS 7 shim Security Update

CentOS Errata and Security Advisory 2020:3217 Moderate

Upstream details at :   https://access.redhat.com/errata/RHSA-2020:3217

The following updated files have been uploaded and are currently
syncing to the mirrors: ( sha256sum Filename )

x86_64:
920e0075aa2fd067ef46bdaeac583b32d8d9871c01db67f1e2ec4b107926df04 shim-unsigned-ia32-15-7.el7_9.x86_64.rpm
cd6842c60c2a012c8d8250c46cfd24c3381b392d5f5556a1755829311e74c732 shim-unsigned-x64-15-7.el7_9.x86_64.rpm

Source:
249512caa1fc6e5956cded0c0a6fdb7e999c97b86dc6c249773dff614d4f746f shim-15-7.el7_9.src.rpm