FreeBSD Security Advisory – IPv6 routers may allow “on-link” IPv6 nodes to create and update the router’s neighbor cache and forwarding information. A malicious IPv6 node sharing a common router but on a different physical segment from another node may be able to spoof Neighbor Discovery messages, allowing it to update router information for the victim node.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/70564/FreeBSD-SA-08.10.nd6.txt
Source: https://packetstormsecurity.com/files/70564/FreeBSD-SA-08.10.nd6.txt.html