# CVE-2026-89612

## Summary

- **CVE ID:** CVE-2026-89612
- **Severity:** CRITICAL
- **CVSS Score:** 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 13, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

ntfs: reject invalid MFT LCNs from boot sector

The NTFS boot sector stores the MFT and MFTMirr locations as unsigned
64-bit LCNs, but parse_ntfs_boot_sector() decoded them into an s64.

A crafted high-bit value could therefore become negative and pass
the existing upper-bound check. The invalid value then propagated into
the MFT zone allocator and could result in an out-of-bounds access to
lcn_empty_bits_per_page.

## Affected Products

- Linux — Linux (11ccc9107dc460de28af90fac1f42404d9802735)
- Linux — Linux (7.1)
- Linux — Linux (0)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)

## References

- [CNA](https://git.kernel.org/stable/c/8f8420b68a6f05ca2b03779d8208814ec539b9e5)
- [CNA](https://git.kernel.org/stable/c/cc9d09fef78410bcd37ac05168cbd5f6dd75d3d2)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.55%
- **EPSS Percentile:** 44.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._