CVE-2026-63805

Estado: AnalizadaAlta (7.8)—

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:

.. 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.

Detalles técnicos trazas, registros y código del informe original

  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

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.13%
Percentil entre todas las CVEs puntuadas: 2
Fecha de la puntuación: 5/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1499.004 Application or System Exploitationimpact75 %
Impacto secundarioT1005 Data from Local Systemcollection60 %

Vector AV:L/PR:L sin UI permite escalada por acceso a memoria del kernel (bad area). El oops sugiere DoS, pero la corrupción de contexto criptográfico también expone datos en memoria.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Threat Intelligence Program Filter Network Traffic Execution Prevention Application Isolation and Sandboxing Exploit Protection Update Software

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

NVD-CWE-noinfo

Referencias

JSON original (NVD)

Mostrar

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  "id": "CVE-2026-63805",
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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: nx - fix nx_crypto_ctx_exit argument\n\nnx_crypto_ctx_shash_exit calls nx_crypto_ctx_exit with crypto_shash_ctx(...)\nbut crypto_shash_ctx gives a nx_crypto_ctx *, not a crypto_tfm *.\n\nFix the type in nx_crypto_ctx_exit and drop the bogus crypto_tfm_ctx\ncall.\n\nThis fixes the following oops:\n\n  BUG: Unable to handle kernel data access at 0xc0403effffffffc8\n  Faulting instruction address: 0xc000000000396cb4\n  Oops: Kernel access of bad area, sig: 11 [#15]\n  Call Trace:\n   nx_crypto_ctx_shash_exit+0x24/0x60\n   crypto_shash_exit_tfm+0x28/0x40\n   crypto_destroy_tfm+0x98/0x140\n   crypto_exit_ahash_using_shash+0x20/0x40\n   crypto_destroy_tfm+0x98/0x140\n   hash_release+0x1c/0x30\n   alg_sock_destruct+0x38/0x60\n   __sk_destruct+0x48/0x2b0\n   af_alg_release+0x58/0xb0\n   __sock_release+0x68/0x150\n   sock_close+0x20/0x40\n   __fput+0x110/0x3a0\n   sys_close+0x48/0xa0\n   system_call_exception+0x140/0x2d0\n   system_call_common+0xf4/0x258\n\n.. which came from hardlink(1) opportunistically using AF_ALG.\n\nThe same problem exists with nx_crypto_ctx_skcipher_exit getting a context\nit wasn't expecting, but apparently nobody hit that for years."
    }
  ],
  "lastModified": "2026-08-17T05:17:17.243",
  "configurations": [
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