CVE-2026-71256
nanoMODBUS Client-Side Out-of-Bounds Read Leading to Wild-Pointer Write via object_id
- 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 stack read leading to a wild-pointer write in nmbs_read_device_identification_basic / recv_read_device_identification_res in nanomodbus.c. A fixed 3-element stack array order[3] = {0,1,2} maps object IDs to buffer indices. The server-supplied object_id field (0-255, read directly from the wire) is used without any bounds check as buf_index = order[object_id].
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
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.