CVE-2026-6684
Medium
Description
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 (Loop with Unreachable Exit Condition). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.
SeverityMedium
CVSS4.6
Exploit probability—
ProductElm-chan Fatfs
PublishedJul 1, 2026
First seenJul 1, 2026
Weakness typeCWE-835CWE-835
How to fix
Update
- elm-chan fatfsr0.16 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| elm-chan fatfs | v < r0.16 | r0.16 |
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