Client memory corruption via unchecked object length
Published Aug 5, 2026 · Updated Aug 5, 2026
Out-of-bounds write in nanoMODBUS through 1.23.0 allows remote attackers to corrupt client memory via a crafted Modbus server response. In recv_read_device_identification_res(), object_length is checked against remaining PDU data but not buffers_length, and the parser then writes a NUL byte at that untrusted offset. A malicious or compromised Modbus server must answer a client's Read Device Identification request; the write can corrupt adjacent stack or heap memory and interrupt or alter the client.
Summary
What happened
Out-of-bounds write in nanoMODBUS through 1.23.0 allows remote attackers to corrupt client memory via a crafted Modbus server response. In recv_read_device_identification_res(), object_length is checked against remaining PDU data but not buffers_length, and the parser then writes a NUL byte at that untrusted offset. A malicious or compromised Modbus server must answer a client's Read Device Identification request; the write can corrupt adjacent stack or heap memory and interrupt or alter the client.
The record
- CVE
- CVE-2026-71255
- Published
- Aug 5, 2026
- Updated
- Aug 5, 2026
- Vendor
- Valerio De Benedetto
- Product
- nanoMODBUS
- Classifications
- CWE-787, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 5, 2026CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <=1.23.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
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Your stack
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