smbd in Samba before 4.4.10 and 4.5.x before 4.5.6 has a denial of service vulnerability (fd_open_atomic infinite loop with high CPU usage and memory consumption) due to wrongly handling dangling symlinks.
www.securityfocus.com/bid/99455
access.redhat.com/errata/RHSA-2017:1950
access.redhat.com/errata/RHSA-2017:2338
access.redhat.com/errata/RHSA-2017:2778
bugs.debian.org/864291
bugzilla.samba.org/show_bug.cgi?id=12572
git.samba.org/?p=samba.git%3Ba=commit%3Bh=10c3e3923022485c720f322ca4f0aca5d7501310
lists.debian.org/debian-lts-announce/2019/04/msg00013.html