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CVE-2026-89779

Estado: RecibidaCrítica (9.1)—

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

fs/ntfs3: validate ef->size covers the record's name and value

When an EA record has a non-zero ef->size, ntfs_read_ea() only checks that the record fits in the remaining buffer (ea_size > bytes), not that ef->size is large enough to hold the record's own name_len + 1 + elength.

A crafted image can pass validation with, e.g., ef->size = 24 but elength = 0xffff. ntfs_get_ea() then trusts elength and copies it out of the undersized record, reading past the kmalloc(info->size) allocation and leaking heap memory to userspace via getxattr():

Leer descripción completaMostrar menos

Compute the size the record needs and require ef->size to cover it.

Detalles técnicos trazas, registros y código del informe original
 BUG: KASAN: slab-out-of-bounds in ntfs_get_ea (fs/ntfs3/xattr.c:302)
 Read of size 65535 at addr ffff888100794550 by task exploit
  __asan_memcpy (mm/kasan/shadow.c:105)
  ntfs_get_ea (fs/ntfs3/xattr.c:302)
  ntfs_getxattr (fs/ntfs3/xattr.c:848)
  __vfs_getxattr (fs/xattr.c:441)
  vfs_getxattr (fs/xattr.c:474)
  do_getxattr (fs/xattr.c:800)
  path_getxattrat (fs/xattr.c:868)
  do_syscall_64 (arch/x86/entry/syscall_64.c:94)

 The buggy address is located 80 bytes inside of
  allocated 84-byte region in cache kmalloc-96

CVSS

Probabilidad de explotación (EPSS)

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.

Acceso remoto sin autenticación (AV:N/PR:N/UI:N) a través de imagen NTFS crafted montada localmente; leak de heap memory via getxattr() de datos sensibles en memoria del kernel.

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

Privileged Account ManagementLimit Access to Resource Over NetworkFilter Network TrafficUpdate SoftwareActive Directory ConfigurationVulnerability Scanning

Tecnologías afectadas (1)

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

Linux — Linux KernelAI

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-89779",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.1,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "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": "333feb7ba84f69f9b423422417aaac54fd9e7c84",
              "lessThan": "b27e68ad818a4ca2cef8f35f97e75d756714c818",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "000a9a72efa4a9df289bab9c9e8ba1639c72e0d6",
              "lessThan": "28a924c7e67e6d71abeb04860b61166fecb027fc",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b",
              "lessThan": "d585ed08308909c7e6fefb4e8a258aeb29b19ff9",
              "versionType": "git"
            },
            {
              "status": "affected",
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              "lessThan": "077df8464cf24f8ffc82fb6efec2ae600686e699",
              "versionType": "git"
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              "lessThan": "aab1880058ac767d3ea9388a9a7221c776c22c44",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b",
              "lessThan": "c8a109c9e23a2c7fd548473dde728b2cb8188146",
              "versionType": "git"
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              "version": "5.15.121",
              "lessThan": "5.15.221",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.1.40",
              "lessThan": "6.1.188",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "fs/ntfs3/xattr.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
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            {
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              "version": "0",
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            {
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              "version": "5.15.221",
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            },
            {
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/ntfs3/xattr.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-16T09:17:08.387",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/077df8464cf24f8ffc82fb6efec2ae600686e699",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/28a924c7e67e6d71abeb04860b61166fecb027fc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/aab1880058ac767d3ea9388a9a7221c776c22c44",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b27e68ad818a4ca2cef8f35f97e75d756714c818",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c22f91d82cb9a29d22bdffdce6c803467984ad0c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c8a109c9e23a2c7fd548473dde728b2cb8188146",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d585ed08308909c7e6fefb4e8a258aeb29b19ff9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: validate ef->size covers the record's name and value\n\nWhen an EA record has a non-zero ef->size, ntfs_read_ea() only checks\nthat the record fits in the remaining buffer (ea_size > bytes), not that\nef->size is large enough to hold the record's own name_len + 1 + elength.\n\nA crafted image can pass validation with, e.g., ef->size = 24 but\nelength = 0xffff. ntfs_get_ea() then trusts elength and copies it out of\nthe undersized record, reading past the kmalloc(info->size) allocation\nand leaking heap memory to userspace via getxattr():\n\n BUG: KASAN: slab-out-of-bounds in ntfs_get_ea (fs/ntfs3/xattr.c:302)\n Read of size 65535 at addr ffff888100794550 by task exploit\n  __asan_memcpy (mm/kasan/shadow.c:105)\n  ntfs_get_ea (fs/ntfs3/xattr.c:302)\n  ntfs_getxattr (fs/ntfs3/xattr.c:848)\n  __vfs_getxattr (fs/xattr.c:441)\n  vfs_getxattr (fs/xattr.c:474)\n  do_getxattr (fs/xattr.c:800)\n  path_getxattrat (fs/xattr.c:868)\n  do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n\n The buggy address is located 80 bytes inside of\n  allocated 84-byte region in cache kmalloc-96\n\nCompute the size the record needs and require ef->size to cover it."
    }
  ],
  "lastModified": "2026-09-16T15:18:07.320",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}