The ChromeClientImpl::createWindow method in WebKit/Source/web/ChromeClientImpl.cpp in Blink, as used in Google Chrome before 52.0.2743.82, does not prevent window creation by a deferred frame, which allows remote attackers to bypass the Same Origin Policy via a crafted web site.
https://codereview.chromium.org/2035973002/
http://www.ubuntu.com/usn/USN-3041-1
http://www.securitytracker.com/id/1036428
http://www.securityfocus.com/bid/92053
http://www.debian.org/security/2016/dsa-3637
http://rhn.redhat.com/errata/RHSA-2016-1485.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00028.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00022.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00021.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00020.html
http://googlechromereleases.blogspot.com/2016/07/stable-channel-update.html