---
cve: "CVE-2026-89593"
severity: "HIGH"
cvss: 7.1
epss: "0.1%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-11 20:19:43"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T12:19:38+02:00"
---

# CVE-2026-89593

> 7.1 HIGH

## Beschreibung

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

hugetlb: only adjust reservation during unmapping if mapcount is 0

Since df7a6d1f6405, __unmap_hugepage_range can adjust reservations.  In
the case of folio mapped in both a parent and a child, if the parent
unmaps the range first, the reservation adjustment will result in an
underflow of the reserved count.  Once the child unmaps the range, the
count is restored.  Change __unmap_hugepage_range() to check the mapcount
before adjusting the reservation.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- Kernel ≥ 6.12.110
- Kernel ≥ 6.18.50
- Kernel ≥ 7.2.4

## Referenzen

- <https://git.kernel.org/stable/c/b0b1b9ca80b795ed2223e76dd787db7067121fb9>
- <https://git.kernel.org/stable/c/a3c65af20cceb7f997847727636b4017326f845d>
- <https://git.kernel.org/stable/c/0f001491e5a2ec69aa9d5dd6b799e5742245f9ea>
- <https://git.kernel.org/stable/c/5120b1e048d48596ffaec1a8412012a91adba73b>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-89593) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_