In FatFS R0.16 and earlier contains a FAT32 integer overflow bug in mount_volume() where fasize *= fs->n_fats can wrap, leading to attacker-controlled file-size metadata and unsafe read lengths in downstream callers. This maps to CWE-190 (Integer Overflow or Wraparound). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (7.6, High). Remote delivery is also possible in OTA/update pipelines. The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Total.
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-fat32-int-of-mnt-cve-2026-6682/ | Third Party Advisory Exploit |
| 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, 14:37
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:a:elm-chan:fatfs:*:*:*:*:*:*:*:* | |
| First Time |
Elm-chan
Elm-chan fatfs |
|
| 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-fat32-int-of-mnt-cve-2026-6682/ - Third Party Advisory, Exploit | |
| References | () https://www.runzero.com/blog/fatfs-bugs/ - Third Party Advisory, Exploit |
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 14:37
NVD link : CVE-2026-6682
Mitre link : CVE-2026-6682
CVE.ORG link : CVE-2026-6682
JSON object : View
Products Affected
elm-chan
- fatfs
CWE
CWE-190
Integer Overflow or Wraparound