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CVE-2026-6688

Estado: AnalizadaAlta (7.6)—

FatFs R0.16 and earlier contains a downstream-caller vulnerability pattern associated with FatFs long filename handling. With LFN enabled, fno.fname can be up to 255 characters; many callers copy it into short fixed buffers without bounds checks, causing overflow. This maps to CWE-120 (Buffer Copy without Checking Size of Input). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (7.6, High). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Total.

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.

AV:P (acceso físico) y CWE-120 (buffer overflow) indican explotación mediante medios extraíbles. El overflow permite ejecución de código arbitrario (T1059) y potencial escalada de privilegios (T1068) en sistemas embebidos.

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

Execution PreventionBehavior Prevention on EndpointDisable or Remove Feature or ProgramThreat Intelligence ProgramRestrict Web-Based ContentPrivileged Account Management

Tecnologías afectadas (1)

Elm-chan — Fatfs

CWE

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-6688",
  "cveTags": [],
  "metrics": {
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      {
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          "role": "CISA Coordinator",
          "options": [
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              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
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              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-07-01T15:06:55.618764Z"
        }
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    "cvssMetricV31": [
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          "attackVector": "PHYSICAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
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        "exploitabilityScore": 0.9
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      "affectedData": [
        {
          "vendor": "ChaN",
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  "published": "2026-07-01T15:17:13.013",
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      "url": "https://elm-chan.org/fsw/ff/",
      "tags": [
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    },
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    {
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    },
    {
      "url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance",
      "tags": [
        "Third Party Advisory",
        "Exploit"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
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  "vulnStatus": "Analyzed",
  "weaknesses": [
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      "description": [
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        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
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    }
  ],
  "lastModified": "2026-07-02T14:38:46.120",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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              "matchCriteriaId": "B99160BB-C4F5-4DA0-9FC9-0723E0633E00",
              "versionEndIncluding": "r0.16"
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  "sourceIdentifier": "44488dab-36db-4358-99f9-bc116477f914"
}