CVE-2026-6684
MediumCVSS 4.6Exploitation Probability (EPSS)
Low risk8th percentile — higher than 8% of all known CVEs
Summary
A vulnerability in FatFs prior to R0.16, using GPT scanning with 'FF_LBA64 = 1', causes an infinite loop during filesystem mounting. The issue stems from an unbounded loop count derived from the GPTH_PtNum field in the GPT header, leading to extremely long or infinite mount times.
Risk Assessment
An attacker with physical access to the device can cause a denial of service (DoS) by mounting a specially crafted media with a malformed GPT table, preventing normal system operation.
Recommendation
Update the FatFs library to version R0.16 or later, which includes a fix limiting the loop count during GPT scanning.
Original NVD description (English source)
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.