CVE-2026-6687

High

Description

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.

SeverityHigh
CVSS7.6
Exploit probability—
ProductElm-chan Fatfs
PublishedJul 1, 2026
First seenJul 1, 2026
Weakness typeCWE-121CWE-121

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
elm-chan fatfsv ≤ r0.16—

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