---
cve: "CVE-2026-74668"
severity: "HIGH"
cvss: 7.8
epss: "19.5%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-08-22 16:16:40"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-07T15:14:21+02:00"
---

# CVE-2026-74668

> 7.8 HIGH

## Beschreibung

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

packet: use consistent hard_header_len in TX_RING send path

tpacket_snd() reads dev->hard_header_len independently for skb
allocation and header construction in tpacket_fill_skb(). Concurrent
netdevice reconfiguration can therefore make the reserved headroom
smaller than the amount later pushed, or make copylen - hard_header_len
negative.

Snapshot hard_header_len once before processing ring frames and use it
for the frame limit, headroom allocation, copy length, and skb
construction. Pass the snapshot to tpacket_fill_skb().

The separate SOCK_DGRAM consistency problem between hard_header_len and
header_ops->create is not addressed here.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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 | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 5.10.267
- Kernel ≥ 5.15.218
- Kernel ≥ 6.1.185
- Kernel ≥ 6.6.152
- Kernel ≥ 6.12.104
- Kernel ≥ 6.18.45
- Kernel ≥ 7.1.9

## Referenzen

- <https://git.kernel.org/stable/c/016763e829cac37b3234eace86fd0a4c560de4a7>
- <https://git.kernel.org/stable/c/21b5953e7494c16a42e6cd8cf110e18d13ae4a6b>
- <https://git.kernel.org/stable/c/27e068d1b35dbec10a3cf268887c94407be4badc>
- <https://git.kernel.org/stable/c/2a73b2c37ee3060a880b53cd24783d93fc7be5f8>
- <https://git.kernel.org/stable/c/9c7e8ff48c377bef18c3d178748aea0575b69ede>
- <https://git.kernel.org/stable/c/d48ea5c9c4c34dc0df621f0e39ed3a16b644621a>
- <https://git.kernel.org/stable/c/d85d2fd54e901637c81d847811e03c662aee13cd>
- <https://git.kernel.org/stable/c/e79f59a8527a49078cfaf8fe8fb5fcefc20c76d2>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-74668) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_