CVE-2026-89661
kernel: NFSD: Prevent post-shutdown use-after-free in unlock_filesystem
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 11, 2026
Updated · October 16, 2026
Description
A flaw was found in the Linux kernel's Network File System Daemon (NFSD). A local administrator with CAP_SYS_ADMIN capabilities can trigger a use-after-free vulnerability by writing to /proc/fs/nfsd/unlock_filesystem after the NFSD server has shut down. This can lead to memory corruption, potentially causing a denial of service.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 6.7CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CWE-825 · Expired Pointer Dereference