A qemu-kvm security update has been released for CentOS 6.

CentOS-announce: CESA-2020:1403 Important CentOS 6 qemu-kvm Security Update

CentOS Errata and Security Advisory 2020:1403 Important

Upstream details at :   https://access.redhat.com/errata/RHSA-2020:1403

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

i386:
5db8741c93f89301f169e688c9884f004d41a5a3c9c2c49763c0ed07eaf7a81a qemu-guest-agent-0.12.1.2-2.506.el6_10.7.i686.rpm

x86_64:
a7c2cb8e14febca4dd4a7554fc9ddaf418b1ed17bc4c40f5850057c7d6ef383f qemu-guest-agent-0.12.1.2-2.506.el6_10.7.x86_64.rpm
f52054992a9464c2d8431237e42950d8b971848b98d551e5abf38b6b0b885421 qemu-img-0.12.1.2-2.506.el6_10.7.x86_64.rpm
4b4468cf63693f8b8204ebc2cfc19f94cf72217ba81a13be4f40712fe9e6a2e5 qemu-kvm-0.12.1.2-2.506.el6_10.7.x86_64.rpm
6ba96df1b300f780321fd79e1d4ce9781d7e32192e6612b10fff180f44fd2a0e qemu-kvm-tools-0.12.1.2-2.506.el6_10.7.x86_64.rpm

Source:
d785b426990e027e3687524057cf19b82c2b73fe289251654732467bed9016f9 qemu-kvm-0.12.1.2-2.506.el6_10.7.src.rpm