The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in Cisco IOS XE 2.1 through 3.17S, IOS XR 2.0.0 through 5.3.2, and NX-OS allows remote attackers to cause a denial of service (packet-processing outage) via crafted ND messages, aka Bug ID CSCuz66542, as exploited in the wild in May 2016.
tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160525-ipv6
www.huawei.com/en/psirt/security-advisories/huawei-sa-20160824-01-ipv6-en
www.securityfocus.com/bid/90872
www.securitytracker.com/id/1035962
www.securitytracker.com/id/1035963
www.securitytracker.com/id/1035964
www.securitytracker.com/id/1035965
www.securitytracker.com/id/1036651