CVE-2026-89672 Linux Kernel NFSd - Broken Access Control

Linux kernel NFS server (nfsd) contains a broken access control vulnerability in NFSACL v2 SETACL path caused by improper handling of ACL mask bits, letting attackers silently remove ACLs, exploit requires crafted NFS SETACL requests.

CVSS base score 9.1 /10
Critical
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.52% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Broken Access Control
Impact
Broken Access Control
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Published
11 September 2026
Updated
15 October 2026

Vendor fix

Update to the latest Linux kernel version containing the fix for nfsd SETACL mask handling.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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