The DHCPv6 relay implementation in Cisco Adaptive Security Appliance (ASA) Software 9.4.1 allows remote attackers to cause a denial of service (device reload) via crafted DHCPv6 packets, aka Bug ID CSCus23248.
http://www.securitytracker.com/id/1035635
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160420-asa-dhcpv6