WebKit/Source/devtools/front_end/devtools.js in the Developer Tools (aka DevTools) subsystem in Blink, as used in Google Chrome before 51.0.2704.79, does not ensure that the remoteFrontendUrl parameter is associated with a chrome-devtools-frontend.appspot.com URL, which allows remote attackers to bypass intended access restrictions via a crafted URL.
https://codereview.chromium.org/2010783002
https://access.redhat.com/errata/RHSA-2016:1201
http://www.ubuntu.com/usn/USN-2992-1
http://www.securitytracker.com/id/1036026
http://www.debian.org/security/2016/dsa-3594
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00005.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00004.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00003.html
http://googlechromereleases.blogspot.com/2016/06/stable-channel-update.html