Necko can access a child on the wrong thread during UDP connections, resulting in a potentially exploitable crash in some instances. This vulnerability affects Firefox < 68.
https://security.gentoo.org/glsa/201908-12
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00017.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html