CVE-2026-89493 Linux Kernel ocfs2 - Out of Bounds Read & Write

Linux kernel ocfs2 contains an out-of-bounds read and write caused by missing validation of rl_used and rl_count fields in refcount block, letting local attackers with CAP_SYS_ADMIN mount crafted or corrupted images to cause memory corruption, exploit requires CAP_SYS_ADMIN privileges.

CVSS base score 8.8 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
EPSS
0.65% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Out of Bounds Read
Impact
Denial Of Service, Remote Code Execution
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/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 ocfs2 refcount block validation.

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