CVE-2026-6682
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->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.
INFO
Published Date :
July 1, 2026, 3:17 p.m.
Last Modified :
July 2, 2026, 2:37 p.m.
Remotely Exploit :
No
Source :
44488dab-36db-4358-99f9-bc116477f914
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 44488dab-36db-4358-99f9-bc116477f914 |
Solution
- Update FatFS to version R0.16a or later.
- Validate file size metadata.
- Sanitize read lengths in downstream callers.
Public PoC/Exploit Available at Github
CVE-2026-6682 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-6682.
| URL | 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 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-6682 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-6682
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
CSS HTML C Dockerfile CMake Shell Python Go Makefile
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-6682 vulnerability anywhere in the article.