fs/nfs/nfs4client.c in the Linux kernel before 5.13.4 has incorrect connection-setup ordering, which allows operators of remote NFSv4 servers to cause a denial of service (hanging of mounts) by arranging for those servers to be unreachable during trunking detection.
Exploitability
AV:AAC:LPR:NUI:NScope
S:UImpact
C:NI:NA:H6.5/CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H