CVE-2026-89697

Estado: RecibidaCrítica (9.1)—

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

nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()

The BOTH_TIME_SET branch calls fh_verify() early so setattr_prepare() can inspect the dentry. This causes nfsd_setattr() to skip fh_want_write(), so notify_change() runs without a mount write reference.

Add the missing fh_want_write() call after the early fh_verify().

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Puntuación base: 9.1

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.74%
Percentil entre todas las CVEs puntuadas: 53
Fecha de la puntuación: 3/10/2026

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.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access45 %
Impacto principalT1565.002 Transmitted Data Manipulationimpact60 %
Impacto secundarioT1499.004 Application or System Exploitationimpact50 %

Vulnerabilidad remota en kernel Linux (AV:N, PR:N) que permite modificación de datos (I:H) y DoS (A:H) mediante omisión de validación en operación SETATTR sin referencia de escritura en montaje.

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

Filter Network Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Encrypt Sensitive Information

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux Kernel^AI

Referencias

JSON original (NVD)

Mostrar

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  "id": "CVE-2026-89697",
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        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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          "version": "3.1",
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          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
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  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()\n\nThe BOTH_TIME_SET branch calls fh_verify() early so setattr_prepare()\ncan inspect the dentry. This causes nfsd_setattr() to skip\nfh_want_write(), so notify_change() runs without a mount write\nreference.\n\nAdd the missing fh_want_write() call after the early fh_verify()."
    }
  ],
  "lastModified": "2026-09-14T13:19:20.060",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}