Memory leak in Cisco IOS XR 5.1.x through 5.1.3, 5.2.x through 5.2.5, and 5.3.x through 5.3.2 on ASR 9001 devices allows remote attackers to cause a denial of service (control-plane protocol outage) via crafted fragmented packets, aka Bug ID CSCux26791.
http://www.securitytracker.com/id/1036585
http://www.securityfocus.com/bid/92399
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160810-iosxr