What is CVE-2026-6684?

CVE-2026-6684 is a medium-severity vulnerability in Chan Fatfs, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 4.6/10. Published 2026-07-01.

How severe is CVE-2026-6684?

Medium severity. CVSS v3 base score is 4.6 out of 10.

Vulnerability in Chan Fatfs

CVE-2026-6684

FatFs prior to R0.16 that use GPT scanning with 'FF_LBA64 = 1' contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835…

CVSS v3 metric

CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Chan Fatfs — versions 0

Weakness classification (CWE)

CWE-835 — Loop with Unreachable Exit Condition (Infinite Loop)

References

44488dab-36db-4358-99f9-bc116477f914 (third-party-advisory)
44488dab-36db-4358-99f9-bc116477f914 (technical-description)
44488dab-36db-4358-99f9-bc116477f914 (product)
44488dab-36db-4358-99f9-bc116477f914 (third-party-advisory)

Frequently asked questions

What is CVE-2026-6684?: CVE-2026-6684 is a medium-severity vulnerability in Chan Fatfs, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 4.6/10. Published 2026-07-01.
How severe is CVE-2026-6684?: Medium severity. CVSS v3 base score is 4.6 out of 10.