A squid security update has been released for CentOS 7.

CentOS-announce: CESA-2020:2040 Important CentOS 7 squid Security Update

CentOS Errata and Security Advisory 2020:2040 Important

Upstream details at :   https://access.redhat.com/errata/RHSA-2020:2040

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

x86_64:
e4deb973049f1956a80841b145c3487576d06bdfed5cc68b439f4c515fa5500b squid-3.5.20-15.el7_8.1.x86_64.rpm
ee23917c7afeaf119f3ba8cce4cafb7f7ecbdc370cfbe714c1751fa5fc3f8b3b squid-migration-script-3.5.20-15.el7_8.1.x86_64.rpm
34a96da435b34f07266dbe42542cd800a004b69429820d804f334d295ed73090 squid-sysvinit-3.5.20-15.el7_8.1.x86_64.rpm

Source:
a981da4d0b1ceddb200cc44bb5f0815d261b59debf72d0815c6bc560a198b841 squid-3.5.20-15.el7_8.1.src.rpm