CVE-2026-6687 HIGH

CVE-2026-6687: FatFs Stack Buffer Overflow via Uncapped exFAT Label Length

Vendor Chan
Product FatFs
Weakness CWE-121
Published July 1, 2026
Last update July 1, 2026
View on NVD All CVEs

CVSS base score

7.6/10
Attack vector Physical
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

July 1, 2026 CVE published
July 1, 2026 Record updated