CVE-2026-6682
HighCVSS 7.6Exploitation Probability (EPSS)
Low risk9th percentile — higher than 9% of all known CVEs
Summary
In FatFS R0.16 and earlier, there is an 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.
Risk Assessment
The risk includes potential remote code execution or privilege escalation in embedded systems using FatFS, especially in OTA/update scenarios, potentially leading to total device compromise.
Recommendation
It is recommended to immediately upgrade to a version of FatFS newer than R0.16 or apply patches that prevent integer overflow in the mount_volume() function.
Original NVD description (English source)
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.