The IPTables firewall in OpenStack Neutron before 7.0.4 and 8.0.0 through 8.1.0 allows remote attackers to bypass an intended ICMPv6-spoofing protection mechanism and consequently cause a denial of service or intercept network traffic via a link-local source address.
https://security.openstack.org/ossa/OSSA-2016-009.html
https://review.openstack.org/#/c/310652/
https://review.openstack.org/#/c/310648/
https://review.openstack.org/#/c/300233/
https://access.redhat.com/errata/RHSA-2016:1474
https://access.redhat.com/errata/RHSA-2016:1473