{"id":"CVE-2026-6682","aliases":["EUVD-2026-40992","GHSA-c25x-vcg6-4ccx"],"status":"published","title":"FatFs Integer Overflow in FAT32 Volume Mount","description":"In FatFS R0.16 and earlier contains a FAT32 integer overflow bug in mount_volume() where fasize *= fs-\u003en_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.","severity":{"version":"3.1","score":7.6,"vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00322,"percentile":0.25424,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-190"],"published":"2026-07-01T13:36:59Z","modified":"2026-10-25T17:10:00Z","products":[{"vendor":"chan","product":"fatfs"},{"vendor":"elm-chan","product":"fatfs"}],"references":[{"url":"https://www.runzero.com/blog/fatfs-bugs/","tags":["third-party-advisory","Third Party Advisory","Exploit"]},{"url":"https://github.com/runZeroInc/vulns-2026-fatfs-chance","tags":["technical-description","exploit","Third Party Advisory","Exploit"]},{"url":"https://elm-chan.org/fsw/ff/","tags":["product","Product"]},{"url":"https://www.runzero.com/advisories/fatfs-fat32-int-of-mnt-cve-2026-6682/","tags":["third-party-advisory","Third Party Advisory","Exploit"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6682"},{"url":"https://elm-chan.org/fsw/ff"},{"url":"https://www.runzero.com/advisories/fatfs-fat32-int-of-mnt-cve-2026-6682"},{"url":"https://www.runzero.com/blog/fatfs-bugs"},{"url":"https://github.com/advisories/GHSA-c25x-vcg6-4ccx"}],"sources":{"cve":[{"id":"CVE-2026-6682","title":"FatFs Integer Overflow in FAT32 Volume Mount","description":"In FatFS R0.16 and earlier contains a FAT32 integer overflow bug in mount_volume() where fasize *= fs-\u003en_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.","status":"published","published":"2026-07-01T13:36:59.935Z","modified":"2026-07-01T15:24:05.86Z","cvss":[{"version":"3.1","score":7.6,"vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T13:49:53.818886Z"}],"euvd":[{"id":"EUVD-2026-40992","description":"In FatFS R0.16 and earlier contains a FAT32 integer overflow bug in mount_volume() where fasize *= fs-\u003en_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.","status":"published","published":"2026-07-01T13:36:59Z","modified":"2026-07-01T15:24:05Z","cvss":[{"version":"3.1","score":7.6,"vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T18:20:19.446061Z"}],"ghsa":[{"id":"GHSA-c25x-vcg6-4ccx","title":"In FatFS R0.16 and earlier contains a FAT32 integer overflow bug in mount_volume() where fasize *...","description":"In FatFS R0.16 and earlier contains a FAT32 integer overflow bug in mount_volume() where fasize *= fs-\u003en_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.","status":"published","published":"2026-07-01T15:35:20Z","modified":"2026-07-01T15:35:27Z","cvss":[{"version":"3.1","score":7.6,"vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T15:09:08.409779Z"}],"nvd":[{"id":"CVE-2026-6682","description":"In FatFS R0.16 and earlier contains a FAT32 integer overflow bug in mount_volume() where fasize *= fs-\u003en_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.","status":"published","published":"2026-07-01T15:17:12.313Z","modified":"2026-10-25T17:10:00.197Z","cvss":[{"version":"3.1","score":7.6,"vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T14:12:27.199837Z"}]}}