CVE-2026-89633 Linux Kernel smb client - Out-of-Bounds Read/Write

Linux kernel smb client contains an out-of-bounds read/write caused by unvalidated DataOffset in coalesce_t2(), letting attackers cause memory corruption or crash, exploit requires crafted SMB packets.

CVSS base score 9.8 /10
Critical
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.47% 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 for this vulnerability.

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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