The developers of FreeBSD have made available the 3rd release candidate of version 12.0. The notable changes are vulnerability and memory leak fixes as listed in the summary below. You can download the ISO/image file here.

If you would like to use SVN to do a source based update of an existing
system, use the "releng/12.0" branch.

A summary of changes since 12.0-RC2 includes:

o Fix for vulnerabilities in NFS server code. (FreeBSD-SA-18:13.nfs)

o The if_ixlv.ko kernel module had been added as a link to if_iavf.ko
  for backwards compatibility when upgrading from earlier releases.

o Various memory leak fixes.

o Various miscellaneous fixes.

A list of changes since 11.2-RELEASE is available in the releng/12.0
release notes:

    https://www.freebsd.org/releases/12.0R/relnotes.html

Please note, the release notes page is not yet complete, and will be
updated on an ongoing basis as the 12.0-RELEASE cycle progresses.

Original announcement: https://lists.freebsd.org/pipermail/freebsd-stable/2018-December/090138.html

Phoronix: https://www.phoronix.com/scan.php?page=news_item&px=FreeBSD-12.0-RC3-Released