CVE-2026-89653 Linux Kernel - Out of Bounds Read/Write

Linux kernel contains a buffer overflow caused by unchecked export_targets ranks in ceph mdsmap decode, letting attackers cause memory corruption by providing ranks >= CEPH_MAX_MDS, exploit requires crafted mdsmap data.

CVSS base score 9.8 /10
Critical
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.50% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Out of Bounds Read/Write
Impact
Denial Of Service
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.

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