---
cve: "CVE-2026-63922"
severity: "CRITICAL"
cvss: 9.8
epss: "0.7%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-19 14:55:24"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-28T07:23:25+01:00"
---

# CVE-2026-63922

> 9.8 CRITICAL

## Beschreibung

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

ipv6: exthdrs: refresh nh after handling HAO option

ip6_parse_tlv() caches skb_network_header(skb) in nh while walking
IPv6 TLVs.

ipv6_dest_hao() may call pskb_expand_head() for a cloned skb, which can
move the skb head and invalidate the cached network header pointer.
Refresh nh after ipv6_dest_hao() returns so any trailing padding or TLVs
are parsed from the current skb head.

This matches the existing pattern used in ip6_parse_tlv() after helpers
that can modify skb header storage.

## CNA-Record (Kanon, cvelistV5)

- CNA: **Linux**
- State: PUBLISHED
- Stand: 2026-10-19 20:17:56
- CNA-CVSS: **9.8** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **total**

## 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 |

## Schwachstellen-Klasse

- **CWE-416** — Use After Free
  The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

## Patch verfügbar (OSV)

- Kernel ≥ 5.10.259
- Kernel ≥ 5.15.210
- Kernel ≥ 6.1.176
- Kernel ≥ 6.6.143
- Kernel ≥ 6.12.93
- Kernel ≥ 6.18.35
- Kernel ≥ 7.0.12

## BSI-Hinweise (deutsch)

- [Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-2403) — _BSI-Einstufung: mittel_
  Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, möglicherweise Sicherheitsmaßnahmen zu umgehen, einen Denial-of-Service-Zustand herbeizuführen oder vertrauliche Informationen offenzulegen.

## Referenzen

- <https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f>
- <https://git.kernel.org/stable/c/f8aabed3ff3e986920cf02a2a2785e08e586b234>
- <https://git.kernel.org/stable/c/1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1>
- <https://git.kernel.org/stable/c/12d957979e4a800167842f1b42be6a606d227ebe>
- <https://git.kernel.org/stable/c/ff375ed1cba81392346c5bfbf0bb7a13b2946f99>
- <https://git.kernel.org/stable/c/751db1b802a067b7fff25880f4e9f9152a171538>
- <https://git.kernel.org/stable/c/9b6dcc0a39fd71752937f0b6b3973e1416085dcf>
- <https://git.kernel.org/stable/c/f7b52afe3592eae66e160586b45a3f2242972c63>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-63922/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_