Cisco IOS XR 5.x through 5.2.5 on NCS 6000 devices allows remote attackers to cause a denial of service (timer consumption and Route Processor reload) via crafted SSH traffic, aka Bug ID CSCux76819.
http://www.securitytracker.com/id/1036295
http://www.securityfocus.com/bid/91748
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160713-ncs6k