libmodbus v3.1.10 has a heap-based buffer overflow vulnerability in read_io_status function in src/modbus.c.

published 2024-05-01 2y ago modified 2026-08-11 3mo ago also EUVD-2023-30586 , JLSEC-2026-1251

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits: 0; none known

Patch / fix

fixed in 1

julia LibModbus_jll 3.1.12+0

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-26793 updated 2025-11-21 cvss 6.2

libmodbus: head buffer overflow in read_io_status()

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 2y ago (2024-05-02)

Exploit prediction

0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-14).

Exploits and checks

github.com https://github.com/stephane/libmodbus/issues/683 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
OSV	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
julia	LibModbus_jll	>=3.1.10+0, <3.1.12+0	3.1.12+0

Affected products

libmodbus libmodbus

Classification

Weakness

CWE-122 Heap-based Buffer Overflow

References

github.com /stephane/libmodbus/issues/683
exploit, issue-tracking, vendor-advisory, web

Sources

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