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CVE-2026-6684

FatFs Infinite Loop in GPT Partition Scan

Published: Jul 1, 2026Updated: Jul 2, 2026 Sources: CVE List NVDCWE-835
4.6MEDIUM
NVD MITRE
EPSS Score
0.2%
Top 89.4%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:PAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:PAttack Vector
Physical
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-835

Affected Products

ChaN
FatFs
elm-chan
fatfs

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://www.runzero.com/blog/fatfs-bugs/
runzero.com
https://github.com/runZeroInc/vulns-2026-fatfs-chance
github.com
https://elm-chan.org/fsw/ff/
elm-chan.org
and 1 more references View all →
News mentions
1

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