VULNERABILITY INTELLIGENCE

CVE-2026-6686

CVSS score4.6 MEDIUM

EPSS probability0.26%

CISA KEVNot currently listed

Published2026-07-01

Last modified2026-10-25

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

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

CWE-908: Use of Uninitialized Resource

Primary references

44488dab-36db-4358-99f9-bc116477f914 — Product
44488dab-36db-4358-99f9-bc116477f914 — Third Party Advisory, Exploit
44488dab-36db-4358-99f9-bc116477f914 — Third Party Advisory
44488dab-36db-4358-99f9-bc116477f914 — Third Party Advisory, Exploit
134c704f-9b21-4f2e-91b3-4a467353bcc0 — Third Party Advisory, Exploit