FatFs R0.16 and earlier contains a divide-by-zero in exFAT sync logic bug when crafted metadata causes n_fatent - 2 to be zero during write/sync operations. This maps to CWE-369 (Divide By Zero). 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). Network-delivered update media can make this remote in some pipelines. The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.
References
| Link | Resource |
|---|---|
| https://elm-chan.org/fsw/ff/ | Product |
| https://github.com/runZeroInc/vulns-2026-fatfs-chance | Third Party Advisory Exploit |
| https://www.runzero.com/advisories/fatfs-exfat-divide-by-zero-cve-2026-6683 | Third Party Advisory |
| https://www.runzero.com/blog/fatfs-bugs/ | Third Party Advisory Exploit |
| https://github.com/runZeroInc/vulns-2026-fatfs-chance | Third Party Advisory Exploit |
Configurations
History
02 Jul 2026, 14:38
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://elm-chan.org/fsw/ff/ - Product | |
| References | () https://github.com/runZeroInc/vulns-2026-fatfs-chance - Third Party Advisory, Exploit | |
| References | () https://www.runzero.com/advisories/fatfs-exfat-divide-by-zero-cve-2026-6683 - Third Party Advisory | |
| References | () https://www.runzero.com/blog/fatfs-bugs/ - Third Party Advisory, Exploit | |
| First Time |
Elm-chan
Elm-chan fatfs |
|
| CPE | cpe:2.3:a:elm-chan:fatfs:*:*:*:*:*:*:*:* |
01 Jul 2026, 16:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/runZeroInc/vulns-2026-fatfs-chance - |
01 Jul 2026, 15:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-07-01 15:17
Updated : 2026-07-02 14:38
NVD link : CVE-2026-6683
Mitre link : CVE-2026-6683
CVE.ORG link : CVE-2026-6683
JSON object : View
Products Affected
elm-chan
- fatfs
CWE
CWE-369
Divide By Zero