CVE-2026-71255

nanoMODBUS through v1.23.0 contains an out-of-bounds write in the Modbus client-side recv_read_device_identification_res function (FC 0x2B/MEI 0x0E, Read Device Identification) in nanomodbus.c. The server-supplied object_length field (0-246) is validated only against the remaining PDU size (res_size_left) and is never validated against the caller-supplied buffers_length parameter.

CVSS v3 8.6 HIGH

8.6^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 4.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/debevv/nanoMODBUS
https://github.com/debevv/nanoMODBUS/blob/master/nanomodbus.c

Configurations

No configuration.

History

23 Oct 2026, 21:10

Type	Values Removed	Values Added
Summary		(es) nanoMODBUS hasta la v1.23.0 contiene una escritura fuera de límites en la función recv_read_device_identification_res() del lado del cliente Modbus (FC 0x2B/MEI 0x0E, Identificación de Lectura de Dispositivo) en nanomodbus.c. El campo object_length (0-246) suministrado por el servidor se valida solo contra el tamaño PDU restante (res_size_left) y nunca se valida contra el parámetro buffers_length suministrado por el llamador. Después de copiar datos con strncpy(buffers_out[buf_index], str, buffers_length), el código escribe incondicionalmente un terminador NUL en buffers_out[buf_index][object_length]. Cuando un servidor Modbus malicioso o comprometido envía una respuesta con object_length mayor o igual que el buffers_length del cliente, esta escritura NUL aterriza más allá del final del búfer proporcionado por el llamador, corrompiendo la memoria adyacente de la pila o del montón en el cliente.

Information

Published : 2026-08-05 12:18

Updated : 2026-10-24 15:10

NVD link : CVE-2026-71255

Mitre link : CVE-2026-71255

CVE.ORG link : CVE-2026-71255

JSON object : View

Products Affected

No product.

CWE

CWE-787

Out-of-bounds Write

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