CVE-2024-36843Public exploitNetwork attack vector

Remote service crash via register-table underwrite

Published May 31, 2024 · Updated Nov 3, 2025

Heap-based buffer overflow in libmodbus 3.1.6 allows remote attackers to crash a Modbus TCP server with crafted requests. A read/write-multiple-register request drives a two-byte write six bytes before the allocated register table, corrupting heap state later consumed by modbus_mapping_free(). The application must expose a libmodbus TCP server using a mapping; the demonstrated consequence is process abort during mapping cleanup.

CVSS severity7.5
High
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in libmodbus 3.1.6 allows remote attackers to crash a Modbus TCP server with crafted requests. A read/write-multiple-register request drives a two-byte write six bytes before the allocated register table, corrupting heap state later consumed by modbus_mapping_free(). The application must expose a libmodbus TCP server using a mapping; the demonstrated consequence is process abort during mapping cleanup.

The record

CVE
CVE-2024-36843
Published
May 31, 2024
Updated
Nov 3, 2025
Vendor
Stéphane Raimbault
Product
libmodbus
Classifications
CWE-122, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 31, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.1.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Stéphane Raimbault · libmodbusversion=3.1.6

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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