CVE-2026-6683

MEDIUMPre-NVD 4.64.6—
EchelonGraph scoreHIGH confidence

Score 4.6 from GitHub Security Advisory published 2026-07-01. a secondary CVSS source baseline 4.6; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
4.6
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.6Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

FatFs R0.16 and earlier contains a divide-by-zero in exFAT sync logic bug when crafted metadata causes n_fatent - 2 to be zero during write/sync operations. This maps to CWE-369 (Divide By Zero). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). Network-delivered update media can make this remote in some pipelines. The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.

CVSS v3
4.6
EG Score
4.6(high)
EG Risk
25(Track)
EG Risk 25/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity46% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
10.7%
KEV
Not listed

Published

July 1, 2026

Last Modified

July 2, 2026

Advisory Details (3)

Auto-updated Jul 3, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic

GitHub - runZeroInc/vulns-2026-fatfs-chance · GitHub

https://github.com/runZeroInc/vulns-2026-fatfs-chance
generic🔴 Active Exploitation

Seven FatFs bugs, one very large blast radius

https://www.runzero.com/blog/fatfs-bugs/
generic🔴 Active Exploitation

FatFs exFAT divide-by-zero in sync/write paths

https://www.runzero.com/advisories/fatfs-exfat-divide-by-zero-cve-2026-6683

Vendor Advisories for CVE-2026-6683(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-23 14:18 UTCEPSS rescore
  2. 2026-07-23 14:18 UTCEPSS rescore
  3. 2026-07-23 03:22 UTCEG score recompute
  4. 2026-07-22 14:08 UTCEPSS rescore
  5. 2026-07-22 14:08 UTCEPSS rescore
  6. 2026-07-21 15:25 UTCEPSS rescore
  7. 2026-07-21 15:25 UTCEPSS rescore
  8. 2026-07-20 17:08 UTCEPSS rescore
  9. 2026-07-19 14:31 UTCEPSS rescore
  10. 2026-07-19 02:29 UTCEPSS rescore
  11. 2026-07-18 10:04 UTCEPSS rescore
  12. 2026-07-16 17:03 UTCEPSS rescore
  13. 2026-07-16 10:52 UTCGHSA enrichment
  14. 2026-07-15 11:07 UTCGHSA enrichment
  15. 2026-07-15 02:00 UTCEPSS rescore
  16. 2026-07-14 11:28 UTCGHSA enrichment
  17. 2026-07-13 22:31 UTCEPSS rescore
  18. 2026-07-13 11:50 UTCGHSA enrichment
  19. 2026-07-13 06:13 UTCEPSS rescore
  20. 2026-07-13 06:13 UTCEPSS rescore
  21. 2026-07-12 12:12 UTCGHSA enrichment
  22. 2026-07-12 05:46 UTCEPSS rescore
  23. 2026-07-11 12:33 UTCGHSA enrichment
  24. 2026-07-10 12:55 UTCGHSA enrichment
  25. 2026-07-09 19:10 UTCEPSS rescore
Show 21 more
  1. 2026-07-09 19:10 UTCEPSS rescore
  2. 2026-07-09 13:15 UTCGHSA enrichment
  3. 2026-07-08 15:16 UTCEPSS rescore
  4. 2026-07-08 15:16 UTCEPSS rescore
  5. 2026-07-08 13:36 UTCGHSA enrichment
  6. 2026-07-07 13:57 UTCGHSA enrichment
  7. 2026-07-07 13:46 UTCEPSS rescore
  8. 2026-07-07 13:46 UTCEPSS rescore
  9. 2026-07-06 16:27 UTCEPSS rescore
  10. 2026-07-06 16:27 UTCEPSS rescore
  11. 2026-07-06 14:19 UTCGHSA enrichment
  12. 2026-07-05 14:38 UTCGHSA enrichment
  13. 2026-07-05 02:31 UTCEPSS rescore
  14. 2026-07-05 02:30 UTCEPSS rescore
  15. 2026-07-04 14:58 UTCGHSA enrichment
  16. 2026-07-04 06:31 UTCEPSS rescore
  17. 2026-07-04 06:31 UTCEPSS rescore
  18. 2026-07-03 15:20 UTCGHSA enrichment
  19. 2026-07-02 15:41 UTCGHSA enrichment
  20. 2026-07-01 16:03 UTCEG score recompute
  21. 2026-07-01 16:03 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-6683?
CVE-2026-6683 is a medium vulnerability published on July 1, 2026. FatFs R0.16 and earlier contains a divide-by-zero in exFAT sync logic bug when crafted metadata causes n_fatent - 2 to be zero during write/sync operations. This maps to CWE-369 (Divide By Zero). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium).…
When was CVE-2026-6683 disclosed?
CVE-2026-6683 was first published in the National Vulnerability Database on July 1, 2026, with the most recent update on July 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-6683 actively exploited?
CVE-2026-6683 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 10.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-6683?
CVE-2026-6683 has a CVSS v3 base score of 4.6 (NVD).
How do I remediate CVE-2026-6683?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-6683, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-6683

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