CentOS Errata and Bugfix Advisory 2016:1402 

Upstream details at : https://rhn.redhat.com/errata/RHBA-2016-1402.html

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

i386:
b78757f04e0625fe3b9a2ee1450ccdf64e2dd15983b7c9093e5dfc9d0784f252  xorg-x11-server-common-1.17.4-9.5.el6.centos.i686.rpm
65155e8765c0a663f3fd35001ccbc5ee542cf3a4a35a7ab4c14e060e7445b327  xorg-x11-server-devel-1.17.4-9.5.el6.centos.i686.rpm
e2a782c836c14e5e69a882203518f5aadaa4e1d973d4e0b6cdb43ba157b1ed61  xorg-x11-server-source-1.17.4-9.5.el6.centos.noarch.rpm
032d5dcaf5419716a64ef57d2eac8e80c0bb76ac22c097e77c2e665fd908da52  xorg-x11-server-Xdmx-1.17.4-9.5.el6.centos.i686.rpm
4c18e18e035f039f5e736750c1e9a189c68bf0a27eb2dcb2d712ba1fec0a9c0d  xorg-x11-server-Xephyr-1.17.4-9.5.el6.centos.i686.rpm
5ec8a5f7d2924e1e3807263ca9205cbc8578a4a2696c88b5991dba17c3994fd1  xorg-x11-server-Xnest-1.17.4-9.5.el6.centos.i686.rpm
68c408a8ec918f4e51a6943431b5dde65e746eff571473516be9ae2362777006  xorg-x11-server-Xorg-1.17.4-9.5.el6.centos.i686.rpm
274c23f8ad0682de786050c69f6417b965f51c9c1e08c6878c87ec127ade5be7  xorg-x11-server-Xvfb-1.17.4-9.5.el6.centos.i686.rpm

x86_64:
dc62ed724bf97d763a5b38832907e075933e6e838c7d7016c677835f87fe939f  xorg-x11-server-common-1.17.4-9.5.el6.centos.x86_64.rpm
65155e8765c0a663f3fd35001ccbc5ee542cf3a4a35a7ab4c14e060e7445b327  xorg-x11-server-devel-1.17.4-9.5.el6.centos.i686.rpm
12c2b41cf93a2f86056eb3c7b2c4d6ee425ca8fd1e5b79f22db0717a16986d72  xorg-x11-server-devel-1.17.4-9.5.el6.centos.x86_64.rpm
e2a782c836c14e5e69a882203518f5aadaa4e1d973d4e0b6cdb43ba157b1ed61  xorg-x11-server-source-1.17.4-9.5.el6.centos.noarch.rpm
4b5766f76b926a7f12100b2d513fc326f5a3fc0a7fd534e406d1cbda3e1d23c3  xorg-x11-server-Xdmx-1.17.4-9.5.el6.centos.x86_64.rpm
cef39ff4c0de6870ffc2996203f5416d7fc1d690bad3214cca6c2e7ed7fae81b  xorg-x11-server-Xephyr-1.17.4-9.5.el6.centos.x86_64.rpm
68e550e1d648a9b8889627aef07d74c511d39e3c7b8f2b08e7f238d600f842d7  xorg-x11-server-Xnest-1.17.4-9.5.el6.centos.x86_64.rpm
fce632c75440a4ccd9aeb82b4421b1173b08bd1ac5f19024e31f7bd48a192d5a  xorg-x11-server-Xorg-1.17.4-9.5.el6.centos.x86_64.rpm
bfc504b39d0b06959a50fde547f6fc7fc343c1f231059e6ebc51cee370008c83  xorg-x11-server-Xvfb-1.17.4-9.5.el6.centos.x86_64.rpm

Source:
a8c73701acee33b210490a67ee5f62648fb0d49e6150376840b1064d2e09f839  xorg-x11-server-1.17.4-9.5.el6.centos.src.rpm