A missing check on incoming client requests can be exploited to cause a situation where the Kea server's lease storage contains leases which are rejected as invalid when the server tries to load leases from storage on restart. If the number of such leases exceeds a hard-coded limit in the Kea code, a server trying to restart will conclude that there is a problem with its lease store and give up. Versions affected: 1.4.0 to 1.5.0, 1.6.0-beta1, and 1.6.0-beta2

A packet containing a malformed DUID can cause the Kea DHCPv6 server process (kea-dhcp6) to exit due to an assertion failure. Versions affected: 1.4.0 to 1.5.0, 1.6.0-beta1, and 1.6.0-beta2.

An extension to hooks capabilities which debuted in Kea 1.4.0 introduced a memory leak for operators who are using certain hooks library facilities. In order to support multiple requests simultaneously, Kea 1.4 added a callout handle store but unfortunately the initial implementation of this store does not properly free memory in every case. Hooks which make use of query4 or query6 parameters in their callouts can leak memory, resulting in the eventual exhaustion of available memory and subsequent failure of the server process. Affects Kea DHCP 1.4.0.