CVE-2026-6687

FatFs Stack Buffer Overflow via Uncapped exFAT Label Length

Published Jul 1, 2026 CVSS 3.1 · 7.6 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Chan
Chan fatfs
Vendors & Products Chan
Chan fatfs
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title FatFs Stack Buffer Overflow via Uncapped exFAT Label Length
Weaknesses CWE-121
References
Metrics cvssV3_1

{'score': 7.6, 'vector': 'CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
runZero
Published
Updated
Jul 1, 2026, 3:06 PM
Reserved
Apr 20, 2026, 3:06 PM
Status
Analyzed
Published
Jul 1, 2026, 3:17 PM
Modified
Oct 25, 2026, 5:10 PM