---
cve: "CVE-2026-63818"
severity: "HIGH"
cvss: 8.4
epss: "0.1%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-19 12:16:54"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T20:04:13+02:00"
---

# CVE-2026-63818

> 8.4 HIGH

## Beschreibung

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

f2fs: validate orphan inode entry count

f2fs_recover_orphan_inodes() trusts the orphan block entry_count when
replaying orphan inodes from the checkpoint pack. A corrupted entry_count
larger than F2FS_ORPHANS_PER_BLOCK makes the recovery loop read past the
ino[] array and interpret footer or following data as inode numbers.

On a crafted image, mounting an unpatched kernel can drive orphan recovery
into f2fs_bug_on() and panic the kernel. Validate entry_count before
consuming entries so corrupted checkpoint data fails the mount with
-EFSCORRUPTED and requests fsck instead.

Set ERROR_INCONSISTENT_ORPHAN as well, so the corruption reason can be
recorded in the superblock s_errors[] field. This gives fsck a persistent
hint even though mount-time orphan recovery failure may leave no chance to
persist SBI_NEED_FSCK through a checkpoint.

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| 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 ≥ 5.10.261
- Kernel ≥ 5.15.212
- Kernel ≥ 6.1.178
- Kernel ≥ 6.6.145
- Kernel ≥ 6.12.96
- Kernel ≥ 6.18.38
- Kernel ≥ 7.1.3

## Referenzen

- <https://git.kernel.org/stable/c/210c210c92d78fdf5051bc55c5c69044b1a2150a>
- <https://git.kernel.org/stable/c/ad101d15716f5a24d1fa82a849f80430c805a3dd>
- <https://git.kernel.org/stable/c/d18c81f5d0ecd5796aa47d66d98f2dd54d8d0f70>
- <https://git.kernel.org/stable/c/d2f236196d542ccd8505736e41c3a1d3f0305f6f>
- <https://git.kernel.org/stable/c/550511a2470f6d204fa07b331f048bd2d3c51280>
- <https://git.kernel.org/stable/c/8aad54746c251f2c2370118df766c0c82e2d2091>
- <https://git.kernel.org/stable/c/2e12381d4495dc8b0ff042c6856022b2e359835c>
- <https://git.kernel.org/stable/c/846c499a65816d13f1186e3090e825e8bb8bcb8b>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-63818) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_