extensions/renderer/gc_callback.cc in Google Chrome before 50.0.2661.94 does not prevent fallback execution once the Garbage Collection callback has started, which allows remote attackers to cause a denial of service (use-after-free) or possibly have unspecified other impact via unknown vectors.
https://security.gentoo.org/glsa/201605-02
https://codereview.chromium.org/1887423002
http://www.securityfocus.com/bid/89106
http://www.debian.org/security/2016/dsa-3564
http://rhn.redhat.com/errata/RHSA-2016-0707.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00048.html
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00004.html
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00003.html
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00002.html
http://googlechromereleases.blogspot.com/2016/04/stable-channel-update_28.html