A shim-signed security update has been released for CentOS 7.

CentOS-announce: CESA-2020:3217 Moderate CentOS 7 shim-signed 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:
46d78ecee751d736f35445677f13e9513bcc73e01c21e8b46e19f6d5f9fdb44f mokutil-15-7.el7_9.x86_64.rpm
44a808272f4977f5c81fcb76b18199b90b5bf4b058f2f418014b8c2f24cb5a83 shim-ia32-15-7.el7_9.x86_64.rpm
bc8bf6b6c2068d3d9477e9a5596ff038ea1dc233cc3609e56571d4982e7d0879 shim-x64-15-7.el7_9.x86_64.rpm

Source:
df836efee4f974f207aa81aa396cda6f72daa95380b4d1f9f6659200c828bf5d shim-signed-15-7.el7_9.src.rpm