« Volver al listado

CVE-2026-89634

Estado: RecibidaCrítica (9.1)—

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

smb: client: fix ALIGN() overflow in symlink_data() error context loop

The check added by commit 7d9a7f1f96cd ("smb/client: fix possible infinite loop and oob read in symlink_data()") compared the post-ALIGN length against the remaining buffer, but ALIGN() itself can overflow: for ErrorDataLength near UINT32_MAX (e.g. 0xFFFFFFF9), ALIGN(x, 8) wraps to 0, so the subsequent bounds check passes, and the loop advances by zero bytes leaving 'p' pointing into stale data.

Fix by checking the raw ErrorDataLength against the remaining space before applying ALIGN(), then checking again after. Since raw_len is bounded by the buffer, raw_len + 7 cannot overflow, so the second check is an exact post-alignment bounds guard.

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.

Desbordamiento de enteros en el kernel Linux accesible remotamente sin autenticación (AV:N/PR:N/UI:N). Permite DoS por bucle infinito y lectura de datos stale.

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 TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication 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 KernelAI

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-89634",
  "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": "76894f3e2f71177747b8b4763fb180e800279585",
              "lessThan": "2b4a25baa0b936fef6915c0459925077b324ecaf",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "76894f3e2f71177747b8b4763fb180e800279585",
              "lessThan": "b89d678f9eafcf8d74885983166ba26b40a04ea0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "76894f3e2f71177747b8b4763fb180e800279585",
              "lessThan": "657372ba6ea50b4474d2a6a610097eae8cd1f3e9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "76894f3e2f71177747b8b4763fb180e800279585",
              "lessThan": "1f824f61d1df52392eaf0b74dfa5659d724fde30",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "76894f3e2f71177747b8b4763fb180e800279585",
              "lessThan": "62a3025983c8c735a3c6fc85a59316f31b59af07",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "76894f3e2f71177747b8b4763fb180e800279585",
              "lessThan": "62656b024efc21c3230eade1a847f25871c3d2bb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2d046892a493d9760c35fdaefc3017f27f91b621",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6.0.16",
              "lessThan": "6.1",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "fs/smb/client/smb2file.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.1",
              "versionType": "semver"
            },
            {
              "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": "6.12.109",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "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/smb/client/smb2file.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:19:49.010",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1f824f61d1df52392eaf0b74dfa5659d724fde30",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2b4a25baa0b936fef6915c0459925077b324ecaf",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/62656b024efc21c3230eade1a847f25871c3d2bb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/62a3025983c8c735a3c6fc85a59316f31b59af07",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/657372ba6ea50b4474d2a6a610097eae8cd1f3e9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b89d678f9eafcf8d74885983166ba26b40a04ea0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix ALIGN() overflow in symlink_data() error context loop\n\nThe check added by commit 7d9a7f1f96cd (\"smb/client: fix possible\ninfinite loop and oob read in symlink_data()\") compared the post-ALIGN\nlength against the remaining buffer, but ALIGN() itself can overflow:\nfor ErrorDataLength near UINT32_MAX (e.g. 0xFFFFFFF9), ALIGN(x, 8)\nwraps to 0, so the subsequent bounds check passes, and the loop\nadvances by zero bytes leaving 'p' pointing into stale data.\n\nFix by checking the raw ErrorDataLength against the remaining space\nbefore applying ALIGN(), then checking again after.  Since raw_len is\nbounded by the buffer, raw_len + 7 cannot overflow, so the second check\nis an exact post-alignment bounds guard."
    }
  ],
  "lastModified": "2026-09-14T13:19:16.653",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}