Cisco NX-OS 6.0(2)U6(0.46) on N3K devices allows remote authenticated users to cause a denial of service (temporary SNMP outage) via an SNMP request for an OID that does not exist, aka Bug ID CSCuw36684.
http://www.securitytracker.com/id/1033717
http://tools.cisco.com/security/center/viewAlert.x?alertId=41240