---
cve: "CVE-2026-68426"
severity: "CRITICAL"
cvss: 9.8
epss: "37%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-08-10 13:20:36"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-18T02:13:49+02:00"
---

# CVE-2026-68426

> 9.8 CRITICAL

## Beschreibung

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

xfrm: fix stale skb->prev after async crypto steals a GSO segment

skb_gso_segment() leaves the segment list head with ->prev pointing at
the last segment, an invariant validate_xmit_skb_list() relies on when
it sets its tail pointer (tail = skb->prev).

When validate_xmit_xfrm() walks a GSO list and some segments are stolen
by async crypto (->xmit() returns -EINPROGRESS), those segments are
unlinked from the list but the head ->prev is never updated.  If the
last segment is the one stolen, the returned head still has ->prev
pointing at it, even though it is now owned by the crypto engine and may
be freed.  validate_xmit_skb_list() later does tail->next = skb, writing
through that stale pointer -- a use-after-free.

Repoint skb->prev at the last retained segment before returning.

## 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 |

## Patch verfügbar (OSV)

- Kernel ≥ 6.18.42
- Kernel ≥ 7.1.6

## Referenzen

- <https://git.kernel.org/stable/c/33e1b0d25ca0d2818c635ff80e6aa0d295e08a98>
- <https://git.kernel.org/stable/c/bbca7cc3b2b4b10afbfee99b81d9ee78f5423046>
- <https://git.kernel.org/stable/c/3f4c3919baf0944ad96580467c302bc6c7758b00>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-68426) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_