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CVE-2026-6683

Full vulnerability record from the local CVENow database.

Description

FatFs R0.16 and earlier contains a divide-by-zero in exFAT sync logic bug when crafted metadata causes n_fatent - 2 to be zero during write/sync operations. This maps to CWE-369 (Divide By Zero). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). Network-delivered update media can make this remote in some pipelines. The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.

Severity
MEDIUM
CVSS score
4.6 (v3.1)
Vulnerability status
Analyzed
Source identifier
44488dab-36db-4358-99f9-bc116477f914
Published
2026-07-01 15:17:12.443000
Last modified
2026-10-25 17:10:00.197000
View original CVE JSON
{
  "id": "CVE-2026-6683",
  "sourceIdentifier": "44488dab-36db-4358-99f9-bc116477f914",
  "published": "2026-07-01T15:17:12.443",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "FatFs R0.16 and earlier contains a divide-by-zero in exFAT sync logic bug when crafted metadata causes n_fatent - 2 to be zero during write/sync operations. This maps to CWE-369 (Divide By Zero). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). Network-delivered update media can make this remote in some pipelines. The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial."
    },
    {
      "lang": "es",
      "value": "FatFs R0.16 y anteriores contiene una división por cero en un error de la lógica de sincronización de exFAT cuando metadatos manipulados causan que n_fatent - 2 sea cero durante operaciones de escritura/sincronización. Esto se mapea a CWE-369 (División por Cero). Vector CVSS v3.1 estimado: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Media). Medios de actualización entregados por red pueden hacer que esto sea remoto en algunas cadenas de suministro. Los vectores SSVC de CISA estimados son Explotación: PoC, Impacto Técnico: Parcial."
    }
  ],
  "affected": [
    {
      "source": "44488dab-36db-4358-99f9-bc116477f914",
      "affectedData": [
        {
          "vendor": "ChaN",
          "product": "FatFs",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0",
              "lessThanOrEqual": "R0.16",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
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        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 4.6,
          "baseSeverity": "MEDIUM",
          "attackVector": "PHYSICAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 0.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-01T15:24:38.147110Z",
          "id": "CVE-2026-6683",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
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  "weaknesses": [
    {
      "source": "44488dab-36db-4358-99f9-bc116477f914",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-369"
        }
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    }
  ],
  "configurations": [
    {
      "nodes": [
        {
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          "negate": false,
          "cpeMatch": [
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              "vulnerable": true,
              "criteria": "cpe:2.3:a:elm-chan:fatfs:*:*:*:*:*:*:*:*",
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  "references": [
    {
      "url": "https://elm-chan.org/fsw/ff/",
      "source": "44488dab-36db-4358-99f9-bc116477f914",
      "tags": [
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    },
    {
      "url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance",
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    },
    {
      "url": "https://www.runzero.com/advisories/fatfs-exfat-divide-by-zero-cve-2026-6683",
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}