CVE-2026-71255

8.6 HIGHpublic exploit available

Published 2026-08-05 · Updated 2026-08-10

AI risk analysis

Summary: The flaw in nanoMODBUS allows for an out-of-bounds write due to improper validation of the object_length field, which can lead to potential code execution or data corruption.
Exploitability: Exploitation is moderately hard as it requires precise control over the object_length field, but preconditions include the presence of a vulnerable version of nanoMODBUS in the system.
Blast radius: If exploited, this flaw could result in significant damage, including unauthorized code execution or data corruption on the affected system.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to nanoMODBUS v1.23.1 or later.

icsmodbusbuffer-overflow

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

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 vector

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

Weaknesses

CWE-787

Public exploit & PoC references

References

Data: NVD (public domain). Analysis: local $0 model. Defensive use only.