CVE-2026-6687 | FatFs R0.16 and earlier contains a stack overflow bug in f_g… | CVSS 7.6 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.

Metadata

CVE ID: CVE-2026-6687
State: PUBLISHED
Assigner: runZero
Reserved: 2026-04-20 15:06 UTC
Published: 2026-07-01 13:57 UTC
Last updated: 2026-07-01 15:06 UTC
Primary CWE: CWE-121
CWE-121 Stack-based buffer overflow
Vendor / Product: ChaN / FatFs
Sources: cve.org · NVD

Severity & Metrics

7.6 HIGH CVSS 3.1

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

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: no
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
ChaN	FatFs	—	0 ≤ R0.16

Weakness (CWE)

CWE	Source	Description
CWE-121	cna	CWE-121 Stack-based buffer overflow

CVSS scores (1)

Score	Severity	Version	Source	Vector
7.6	HIGH	3.1	cna	CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

References (4)