CVE-2026-6682

In FatFS R0.16 and earlier contains a FAT32 integer overflow bug in mount_volume() where fasize *= fs->n_fats can wrap, leading to attacker-controlled file-size metadata and unsafe read lengths in downstream callers. This maps to CWE-190 (Integer Overflow or Wraparound). 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). Remote delivery is also possible in OTA/update pipelines. The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Total.

CVSS v3 7.6 HIGH

7.6^/10

CVSS v3 : HIGH

Vector :

Exploitability : 0.9 / Impact : 6.0

Attack Vector PHYSICAL

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

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-fat32-int-of-mnt-cve-2026-6682/	Third Party Advisory Exploit
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) En FatFS R0.16 y versiones anteriores contiene un error de desbordamiento de entero FAT32 en mount_volume() donde fasize *= fs -> n_fats puede desbordarse, lo que lleva a metadatos de tamaño de archivo controlados por el atacante y longitudes de lectura inseguras en los llamadores posteriores. Esto se corresponde con CWE-190 (Desbordamiento de Entero o Envoltura). Vector CVSS v3.1 estimado: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (7.6, Alto). La entrega remota también es posible en las cadenas de actualización OTA. Los vectores SSVC de CISA estimados son Explotación: PoC, Impacto Técnico: Total.

Information

Published : 2026-07-01 15:17

Updated : 2026-10-25 17:10

NVD link : CVE-2026-6682

Mitre link : CVE-2026-6682

CVE.ORG link : CVE-2026-6682

JSON object : View

Products Affected

elm-chan

fatfs

CWE

CWE-190

Integer Overflow or Wraparound

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