CVE-2026-6682
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.
- Score
- CVSS 3.1 7.6 High
- Status
- Analyzed - 44488dab-36db-4358-99f9-bc116477f914
- Published
- 2026-07-01
- Last modified
- 2026-10-25
- Weaknesses
- CWE-190
Affected products
References
- https://www.runzero.com/blog/fatfs-bugs/
- https://github.com/runZeroInc/vulns-2026-fatfs-chance
- https://elm-chan.org/fsw/ff/
- https://www.runzero.com/advisories/fatfs-fat32-int-of-mnt-cve-2026-6682/
