Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
https://usn.ubuntu.com/3557-1/
https://security.gentoo.org/glsa/201607-01
http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-14016.patch
http://www.squid-cache.org/Advisories/SQUID-2016_4.txt
http://www.securitytracker.com/id/1035458
http://rhn.redhat.com/errata/RHSA-2016-2600.html
http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html