CVE-2026-6687

7.6 HIGH 0.3% exploit odds No fix listed Memory safety

What it is

FatFs R0.16 and earlier contains a stack overflow bug in f_getlabel() because exFAT label length (XDIR_NumLabel) is trusted without enforcing spec maximums. This maps to CWE-121 (Stack-based Buffer Overflow). 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). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Total.

At a glance

Exploitability: Can be exploited with physical access without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

2026-07-01 15:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-25 17:10 UTC Last updatedMost recent change to the record

Details

Published: 2026-07-01 15:17 UTC
Last modified: 2026-10-25 17:10 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-121
Record status: Analyzed

Affected

elm-chan Fatfs ≤ r0.16

Attack profile CVSS 3.1 · 7.6

Attack vector: Physical
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

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References

NVD record · CVE.org record