CVE-2026-6687

FatFs R0.16 and earlier contains a stack overflow bug in f_getlabel() because exFAT label length (XDIR_NumLabel) is trusted without enforcing spec maximums. This maps to CWE-121 (Stack-based Buffer Overflow). 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 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-exfat-label-len-of-cve-2026-6687/	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 un error de desbordamiento de pila en f_getlabel() porque la longitud de la etiqueta exFAT (XDIR_NumLabel) se confía en ella sin aplicar los máximos de la especificación. Esto se mapea a CWE-121 (Desbordamiento de búfer basado en pila). 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). 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-2026-6687

Mitre link : CVE-2026-6687

CVE.ORG link : CVE-2026-6687

JSON object : View

Products Affected

elm-chan

fatfs

CWE

CWE-121

Stack-based Buffer Overflow

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