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CVE-2026-6688
7.6 HIGH
- CVSS version (CVSS): 3.1
- Attack Vector (AV): Physical (P)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Changed (C)
- Confidentiality (C): High (H)
- Integrity (I): High (H)
- Availability (A): High (H)
- Modified Attack Vector (MAV): Physical (P)
- Modified Attack Complexity (MAC): Low (L)
- Modified Privileges Required (MPR): None (N)
- Modified User Interaction (MUI): None (N)
- Modified Confidentiality (MC): High (H)
- Modified Scope (MS): Changed (C)
- Modified Integrity (MI): High (H)
- Modified Availability (MA): High (H)
Activity log
- Created suggestion
FatFs Buffer Overflow via Unbounded LFN Filename Copy
FatFs R0.16 and earlier contains a downstream-caller vulnerability pattern associated with FatFs long filename handling. With LFN enabled, fno.fname can be up to 255 characters; many callers copy it into short fixed buffers without bounds checks, causing overflow. This maps to CWE-120 (Buffer Copy without Checking Size of Input). 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.
References
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https://www.runzero.com/blog/fatfs-bugs/ third-party-advisory
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https://elm-chan.org/fsw/ff/ product
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https://www.runzero.com/advisories/fatfs-long-fn-of-downstream-cve-2026-6688/ third-party-advisory
Affected products
FatFs
- =<R0.16
Matching in nixpkgs
pkgs.python312Packages.pyfatfs
None
Package maintainers
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@vlaci László Vaskó <laszlo.vasko@outlook.com>