The remote host is vulnerable to a Denial of Service (DoS) attack.
The remote Cisco device has enabled IPv6. On many Cisco devices, it may be possible to make the remote device crash when sending it malformed IPv6 packets. These vulnerabilities would allow a remote attacker to potentially cause the Cisco machine to reboot repeatedly, causing a loss of availability.
Ensure that IPv6 functionality is required and then ensure that a patched version of Cisco IOS is installed.