In FreeBSD before 11.1-STABLE(r332066) and 11.1-RELEASE-p10, due to insufficient initialization of memory copied to userland in the network subsystem, small amounts of kernel memory may be disclosed to userland processes. Unprivileged authenticated local users may be able to access small amounts of privileged kernel data.
https://security.FreeBSD.org/advisories/FreeBSD-EN-18:05.mem.asc