CVE-2013-5560: The IPv6 implementation in Cisco Adaptive Security Appliance (ASA) Software 9.1.3 and earlier, when NAT64 o...

Security readout for executives and security teams

This flaw can make a vulnerable Cisco ASA firewall reload when it handles specially crafted IPv6 NAT traffic. A reload can interrupt network access and security enforcement. Exposure depends on running ASA Software 9.1.3 or earlier with NAT64 or NAT66 enabled. Likely limited to Cisco ASA deployments on software 9.1.3 or earlier where NAT64 or NAT66 is enabled and reachable by relevant IPv6 traffic. Treat as a targeted availability risk for older ASA firewalls using IPv6 NAT. Prioritize inventory and vendor-guided remediation, especially where firewall reloads would disrupt customer, remote access, or production traffic. Mitigation focus: Review Cisco's advisory for vendor-supported fixed releases or workarounds.; Inventory Cisco ASA appliances and prioritize versions 9.1.3 or earlier.; Identify whether NAT64 or NAT66 is enabled on any ASA device..

Prepared

Jun 14, 2026, 15:13 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.