---
cve: "CVE-2026-63805"
severity: "HIGH"
cvss: 7.8
epss: "13%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-19 12:16:53"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-12T16:31:04+02:00"
---

# CVE-2026-63805

> 7.8 HIGH

## Beschreibung

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

crypto: nx - fix nx_crypto_ctx_exit argument

nx_crypto_ctx_shash_exit calls nx_crypto_ctx_exit with crypto_shash_ctx(...)
but crypto_shash_ctx gives a nx_crypto_ctx *, not a crypto_tfm *.

Fix the type in nx_crypto_ctx_exit and drop the bogus crypto_tfm_ctx
call.

This fixes the following oops:

  BUG: Unable to handle kernel data access at 0xc0403effffffffc8
  Faulting instruction address: 0xc000000000396cb4
  Oops: Kernel access of bad area, sig: 11 [#15]
  Call Trace:
   nx_crypto_ctx_shash_exit+0x24/0x60
   crypto_shash_exit_tfm+0x28/0x40
   crypto_destroy_tfm+0x98/0x140
   crypto_exit_ahash_using_shash+0x20/0x40
   crypto_destroy_tfm+0x98/0x140
   hash_release+0x1c/0x30
   alg_sock_destruct+0x38/0x60
   __sk_destruct+0x48/0x2b0
   af_alg_release+0x58/0xb0
   __sock_release+0x68/0x150
   sock_close+0x20/0x40
   __fput+0x110/0x3a0
   sys_close+0x48/0xa0
   system_call_exception+0x140/0x2d0
   system_call_common+0xf4/0x258

.. which came from hardlink(1) opportunistically using AF_ALG.

The same problem exists with nx_crypto_ctx_skcipher_exit getting a context
it wasn't expecting, but apparently nobody hit that for years.

## 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 ≥ 6.18.38
- Kernel ≥ 7.1.3

## Referenzen

- <https://git.kernel.org/stable/c/8d8507a457667f23477a15496b91908a5b5b7cf3>
- <https://git.kernel.org/stable/c/833033e6e55acf11304ff7bbbdf18351d139c281>
- <https://git.kernel.org/stable/c/4e67f504ee9ded15e256b64f4fde150e917381d7>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-63805) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_