Cisco IOS 15.2 through 15.6 and IOS XE 3.6 through 3.17 and 16.1 allow remote attackers to cause a denial of service (device restart) via a malformed IPv6 Protocol Independent Multicast (PIM) register packet, aka Bug ID CSCuy16399.
https://ics-cert.us-cert.gov/advisories/ICSA-16-287-04
http://www.securitytracker.com/id/1036914
http://www.securityfocus.com/bid/93211
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160928-msdp