CVE-2026-89640 Linux Kernel - Data Tampering & Denial of Service

Linux kernel contains a vulnerability in cifs_remap_file_range() caused by loff_t underflow when len is 0, letting attackers cause file range corruption, exploit requires crafted FSCTL_DUPLICATE_EXTENTS_TO_FILE request.

CVSS base score 7.1 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
EPSS
0.13% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Data Tampering
Impact
Data Tampering, Denial Of Service
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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 cifs_remap_file_range() loff_t underflow.

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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