Vulnerability Details CVE-2026-6682
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 11.3%
CVSS Severity
CVSS v3 Score 7.6
Products affected by CVE-2026-6682
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cpe:2.3:a:elm-chan:fatfs:r0.07a
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cpe:2.3:a:elm-chan:fatfs:r0.07c
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cpe:2.3:a:elm-chan:fatfs:r0.07e
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cpe:2.3:a:elm-chan:fatfs:r0.08
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cpe:2.3:a:elm-chan:fatfs:r0.08a
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cpe:2.3:a:elm-chan:fatfs:r0.08b
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cpe:2.3:a:elm-chan:fatfs:r0.09
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cpe:2.3:a:elm-chan:fatfs:r0.09a
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cpe:2.3:a:elm-chan:fatfs:r0.09b
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cpe:2.3:a:elm-chan:fatfs:r0.10
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cpe:2.3:a:elm-chan:fatfs:r0.10a
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cpe:2.3:a:elm-chan:fatfs:r0.10b
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cpe:2.3:a:elm-chan:fatfs:r0.10c
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cpe:2.3:a:elm-chan:fatfs:r0.11
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cpe:2.3:a:elm-chan:fatfs:r0.11a
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cpe:2.3:a:elm-chan:fatfs:r0.12
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cpe:2.3:a:elm-chan:fatfs:r0.12a
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cpe:2.3:a:elm-chan:fatfs:r0.12b
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cpe:2.3:a:elm-chan:fatfs:r0.12c
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cpe:2.3:a:elm-chan:fatfs:r0.13
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cpe:2.3:a:elm-chan:fatfs:r0.13a
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cpe:2.3:a:elm-chan:fatfs:r0.13b
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cpe:2.3:a:elm-chan:fatfs:r0.13c
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cpe:2.3:a:elm-chan:fatfs:r0.14
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cpe:2.3:a:elm-chan:fatfs:r0.14a
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cpe:2.3:a:elm-chan:fatfs:r0.14b
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cpe:2.3:a:elm-chan:fatfs:r0.15
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cpe:2.3:a:elm-chan:fatfs:r0.15a
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cpe:2.3:a:elm-chan:fatfs:r0.15b
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cpe:2.3:a:elm-chan:fatfs:r0.16