A spamassassin Security Update has been released for CentOS 7.

CentOS Errata and Security Advisory 2018:2916 Important

Upstream details at :   https://access.redhat.com/errata/RHSA-2018:2916

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

x86_64:
e88baef880f698f569f17e78b72bbb5d4c45d32b7687ea554e380207b0aa7919 spamassassin-3.4.0-5.el7_7.x86_64.rpm

Source:
3ee5081e2324ed9a14dff6f6db987d3f0d7fbecbe4b89132c470d02280bb08e7 spamassassin-3.4.0-5.el7_7.src.rpm