---
cve: "CVE-2026-80738"
severity: "HIGH"
cvss: 7.3
epss: "26.3%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-03 13:06:12"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-07T06:07:05+02:00"
---

# CVE-2026-80738

> 7.3 HIGH

## Beschreibung

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

bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie

bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie accept a socket pointer
'sk' with argument type ARG_PTR_TO_BTF_ID_SOCK_COMMON. However, they access
sk->sk_protocol without validating whether 'sk' represents a full socket.

Fix this issue by checking sk->sk_state != TCP_LISTEN before inspecting
sk->sk_protocol in both bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie.
Since mini-sockets are never in the TCP_LISTEN state, the condition
short-circuits and prevents dereferencing fullsock-specific fields.

## CVSS-Vektor

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

| 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 | Gering | warn |

## Patch verfügbar (OSV)

- Kernel ≥ 7.1.9

## Referenzen

- <https://git.kernel.org/stable/c/23f682083aa3fbc0c49667818efd6979a8bc5ac2>
- <https://git.kernel.org/stable/c/31a420a822ff92e2090bd5d65efe8e34e2d6d9b8>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-80738) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_