CVEvulnerability
CVE-2026-6688
7.6 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-07-01
- Last modified
- 2026-10-25
- Assigner
- 44488dab-36db-4358-99f9-bc116477f914
- CVSS 3.1 (44488dab-36db-4358-99f9-bc116477f914)
- 7.6 HIGH — CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Weaknesses
- CWE-120
Description
FatFs R0.16 and earlier contains a downstream-caller vulnerability pattern associated with FatFs long filename handling. With LFN enabled, fno.fname can be up to 255 characters; many callers copy it into short fixed buffers without bounds checks, causing overflow. This maps to CWE-120 (Buffer Copy without Checking Size of Input). 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). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Total.
Affected configurations
• elm-chan fatfs (<= r0.16)
Related
Weakness · CWE (1)
- CWE-120 Buffer Copy without Checking Size of Input weakness
References
- 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-long-fn-of-downstream-cve-2026-6688/ 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