libndp before 1.6, as used in NetworkManager, does not properly validate the origin of Neighbor Discovery Protocol (NDP) messages, which allows remote attackers to conduct man-in-the-middle attacks or cause a denial of service (network connectivity disruption) by advertising a node as a router from a non-local network.
https://rhn.redhat.com/errata/RHSA-2016-1086.html
https://github.com/jpirko/libndp/commit/a4892df306e0532487f1634ba6d4c6d4bb381c7f
https://github.com/jpirko/libndp/commit/2af9a55b38b55abbf05fd116ec097d4029115839
http://www.ubuntu.com/usn/USN-2980-1
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html