A vulnerability was discovered and corrected in ISC dhcp:

ISC DHCP server 4.0 before 4.0.2, 4.1 before 4.1.2, and 4.2 before
4.2.0-P1 allows remote attackers to cause a denial of service (crash)
via a DHCPv6 packet containing a Relay-Forward message without an
address in the Relay-Forward link-address field (CVE-2010-3611).

The updated packages have been upgraded to 4.1.2 which is not
vulnerable to this issue.