Cisco IPv6 advisory
Cisco have released a security advisory about multiple crafted IPv6 packets causing a reload. It seems that on a number of IOS versions with IPv6 enabled, a remote attacker can cause the router to reboot by crafting a particular series of IPv6 packets. Those of us who have been updating our IOSes recently for other reasons are in luck, as relatively recent versions of IOS appear to be safe.
This appears at the same time as two other Cisco security announcements. Busy day.