---
cve: "CVE-2026-72408"
severity: "CRITICAL"
cvss: 10.0
epss: "41%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-08-15 06:22:14"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-03T01:27:26+02:00"
---

# CVE-2026-72408

> 10.0 CRITICAL

## Beschreibung

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

geneve: gate GRO hint in geneve_gro_complete() on gs->gro_hint

geneve_gro_receive() reads the GRO hint through geneve_sk_gro_hint_off(),
which honours it only when the socket enabled IFLA_GENEVE_GRO_HINT
(gs->gro_hint). geneve_gro_complete() instead calls the low-level
geneve_opt_gro_hint_off() and acts on the hint unconditionally.

On a tunnel without the hint, receive aggregates the frames as plain
ETH_P_TEB while complete still honours an attacker-supplied hint option: it
inflates gh_len by gro_hint->nested_hdr_len (u8) and redirects the dispatch
type, so the inner gro_complete handler runs at nhoff + gh_len, an offset
receive never pulled nor validated, reading out of bounds of the skb head:

  BUG: KASAN: slab-out-of-bounds in ipv6_gro_complete (net/ipv6/ip6_offload.c:196)
  Read of size 1 at addr ffff88800fe91980 by task exploit/153
   ipv6_gro_complete (net/ipv6/ip6_offload.c:196)
   geneve_gro_complete (drivers/net/geneve.c:965)
   udp_gro_complete (net/ipv4/udp_offload.c:940)
   inet_gro_complete (net/ipv4/af_inet.c:1621)
   __gro_flush (net/core/gro.c:306)

Gate the complete path on gs->gro_hint too via geneve_sk_gro_hint_off(), so
both paths agree. Tunnels that enable the hint are unaffected.

## CVSS-Vektor

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

## Patch verfügbar (OSV)

- Kernel ≥ 7.1.5

## Referenzen

- <https://git.kernel.org/stable/c/49c2e7c0a69999a75ef5eaebe1559a20d0b3c15a>
- <https://git.kernel.org/stable/c/2651c174445884ac9e85622aeade9c1f7b98d8e5>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-72408) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_