CVE-2026-89687

Estado: RecibidaAlta (7.5)—

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

nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file

->atomic_open is permitted to return success without actually opening the file. It indicates this by calling finish_no_open(). This means dentry_create() can return a file which hasn't been opened. This is extremely unlikely as ->atomic_open handlers typically use finish_no_open() only for already existing files, and dentry_create() isn't called in that case, and the parent being locked should prevent races.

However out of an abundance of caution it seems wise to teach nfsd to only use the file returned by dentry_create() if FMODE_OPENED is set, indicating that it has in fact been opened.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 7.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.49%
Percentil entre todas las CVEs puntuadas: 40
Fecha de la puntuación: 6/10/2026

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 access60 %
Impacto principalT1499 Endpoint Denial of Serviceimpact55 %

Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application Isolation and Sandboxing

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

{
  "id": "CVE-2026-89687",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "64a989dbd144e0622371396461b11335459692d2",
              "lessThan": "a95a1cffacd0203100297001719160160f443dd6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "64a989dbd144e0622371396461b11335459692d2",
              "lessThan": "5859cc01fee06a2cd7458905a9593082fbab06e1",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/nfsd/filecache.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "7.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/nfsd/filecache.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:19:55.663",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/5859cc01fee06a2cd7458905a9593082fbab06e1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a95a1cffacd0203100297001719160160f443dd6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: ensure nfsd_file_do_acquire() does not use a non-opened file\n\n->atomic_open is permitted to return success without actually opening\nthe file.  It indicates this by calling finish_no_open().\nThis means dentry_create() can return a file which hasn't been opened.\nThis is extremely unlikely as ->atomic_open handlers typically\nuse finish_no_open() only for already existing files, and dentry_create()\nisn't called in that case, and the parent being locked should prevent\nraces.\n\nHowever out of an abundance of caution it seems wise to teach nfsd to\nonly use the file returned by dentry_create() if FMODE_OPENED is set,\nindicating that it has in fact been opened."
    }
  ],
  "lastModified": "2026-09-13T07:17:34.493",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}