CVE-2026-89664 Linux Kernel NFSd - Resource Leak

Linux kernel contains a resource leak vulnerability in NFS server (nfsd) caused by missing release of OPEN-decoded POSIX ACLs in nfsd4 operations, letting attackers cause resource leaks, exploit requires sending malformed OPEN compound requests with valid POSIX ACL attributes.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.49% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Resource Leak
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
11 September 2026
Updated
15 October 2026

Vendor fix

Update to the latest Linux kernel version containing the fix for nfsd OPEN-decoded POSIX ACL release.

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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