The IPv6 snooping functionality in the first-hop security subsystem in Cisco IOS 12.2, 15.0, 15.1, 15.2, 15.3, 15.4, and 15.5 and IOS XE 3.2SE, 3.3SE, 3.3XO, 3.4SG, 3.5E, and 3.6E before 3.6.3E; 3.7E before 3.7.2E; 3.9S and 3.10S before 3.10.6S; 3.11S before 3.11.4S; 3.12S and 3.13S before 3.13.3S; and 3.14S before 3.14.2S does not properly implement the Control Plane Protection (aka CPPr) feature, which allows remote attackers to cause a denial of service (device reload) via a flood of ND packets, aka Bug ID CSCus19794.
Cisco IOS XE 2.x and 3.x before 3.10.6S, 3.11.xS through 3.13.xS before 3.13.3S, and 3.14.xS through 3.15.xS before 3.15.1S allows remote attackers to cause a denial of service (device reload) via IPv4 packets that require NAT and MPLS actions, aka Bug ID CSCut96933.
Cisco IOS 15.4S, 15.4SN, and 15.5S and IOS XE 3.13S and 3.14S allow remote attackers to cause a denial of service (device crash) by including an IA_NA option in a DHCPv6 Solicit message on the local network, aka Bug ID CSCur29956.