CVE-2026-6684: ChaN FatFs · Infinite Loop
Affects ChaN FatFsSource CVE Database V5
Not known to be exploited · CVSS 4.6 Medium : upgrade to R0.16 when convenient.
Data as of 13 Nov 2026, 23:54 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in R0.16
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade ChaN FatFs to R0.16.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ChaNFatFs | Affected
| Fixed in
|
AI-suggested
If you cannot patch yet, avoid using FatFs with FF_LBA64 = 1 on systems where GPT scanning is required, or implement external controls to limit mount-time operations.
Description
FatFs prior to R0.16 that use GPT scanning with 'FF_LBA64 = 1' contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835 (Loop with Unreachable Exit Condition). 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). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.