CVE-2026-6683

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.

CVSS v3 4.6 MEDIUM

4.6^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 0.9 / Impact : 3.6

Attack Vector PHYSICAL

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://elm-chan.org/fsw/ff/	Product
https://github.com/runZeroInc/vulns-2026-fatfs-chance	Third Party Advisory Exploit
https://www.runzero.com/advisories/fatfs-exfat-divide-by-zero-cve-2026-6683	Third Party Advisory
https://www.runzero.com/blog/fatfs-bugs/	Third Party Advisory Exploit
https://github.com/runZeroInc/vulns-2026-fatfs-chance	Third Party Advisory Exploit

Configurations

Configuration 1 (hide)

cpe:2.3:a:elm-chan:fatfs:*:*:*:*:*:*:*:*

History

25 Oct 2026, 17:10

Type	Values Removed	Values Added
Summary		(es) 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.

Information

Published : 2026-07-01 15:17

Updated : 2026-10-25 17:10

NVD link : CVE-2026-6683

Mitre link : CVE-2026-6683

CVE.ORG link : CVE-2026-6683

JSON object : View

Products Affected

elm-chan

fatfs

CWE

CWE-369

Divide By Zero

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