CVE-2026-71254
nanoMODBUS Server-Side Out-of-Bounds Write in handle_read_file_record()
- State
- Published
- Severity
- 9.8 Critical
- Published
- Aug 5, 2026
- Updated
- Aug 10, 2026
- Reserved
- Aug 5, 2026
Description
nanoMODBUS through v1.23.0 contains an out-of-bounds write in the Modbus server-side handle_read_file_record function (FC 0x14, Read File Record) in nanomodbus.c. The function validates that the total request size does not exceed 245 bytes and that each sub-request's record_length is at most 124, but it never validates the CUMULATIVE response size across all sub-requests before processing them.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | TuranSec |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
nanoMODBUSdebevv |
|
References
- https://github.com/debevv/nanoMODBUSthird-party-advisory
- https://github.com/debevv/nanoMODBUS/blob/master/nanomodbus.cthird-party-advisory
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