Dashboard / CVE-2026-6686

CVE-2026-6686

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 44/100
Published: 2026-07-01 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth No Interaction Conf. Impact

CVSS Vector Breakdown

AV: Physical
AC: Low
PR: None
UI: None
S: Unchanged
C: High
I: None
A: None

Description

FatFs R0.16 and earlier contains an uninitialized cluster exposure when f_lseek() extends files beyond EOF without zero-filling newly allocated clusters. This maps to CWE-908 (Use of Uninitialized Resource). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
elm-chan fatfs < r0.16

References & Advisories (4)

https://www.runzero.com/blog/fatfs-bugs/
Third Party Advisory Exploit

Bug Bounty Relevance

44 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

4.6 / 10.0 v3.1
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS — Exploitation Probability

0.26%
Raw Score 0.002550
Percentile 17.1%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00255
2026-10-28
0.00255

Intelligence Sources

nvd ref →

External Links