---
cve: "CVE-2026-89612"
severity: "CRITICAL"
cvss: 9.8
epss: "71.8%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-11 20:19:46"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-15T08:42:50+02:00"
---

# CVE-2026-89612

> 9.8 CRITICAL

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 7.2.4

## Referenzen

- <https://git.kernel.org/stable/c/8f8420b68a6f05ca2b03779d8208814ec539b9e5>
- <https://git.kernel.org/stable/c/cc9d09fef78410bcd37ac05168cbd5f6dd75d3d2>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-89612) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_