CVE-2026-89674 Linux Kernel - Buffer Overflow & Information Disclosure

Linux kernel contains a buffer overflow and information disclosure vulnerability caused by incorrect XDR length calculation in nfsd4_ff_encode_layoutget, letting remote attackers cause out-of-bounds write or leak uninitialized kernel memory, exploit requires crafted NFSv4 requests.

CVSS base score 9.8 /10
Critical
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.51% chance of exploitation in 30 days
View the NVD record ↗

Details

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

Vendor fix

Update to the latest Linux kernel version containing the fix for nfsd4_ff_encode_layoutget XDR length calculation.

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

← All CVEs