Cisco NX-OS on Nexus 7000 series switches does not properly handle certain line-card replacements, which might allow remote authenticated users to cause a denial of service (memory consumption) via a crafted configuration that references interfaces that do not exist on the new card, aka Bug ID CSCud44300.
http://www.securitytracker.com/id/1028018
http://tools.cisco.com/security/center/content/CiscoSecurityNotice/CVE-2012-6396