CVE-2024-8403Network attack vector

Ethernet communication outage via malformed SLMP packets

Published Nov 19, 2024 · Updated Mar 31, 2026

Improper input validation in FX5-ENET and FX5-ENET/IP firmware allows remote attackers to interrupt module Ethernet communication. The Ethernet port accepts specially crafted SLMP packets without correctly validating their specified input type, leaving communication in a denial-of-service state. No authentication or user action is required, and restoring communication requires a module reset.

CVSS severity7.5
High
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in FX5-ENET and FX5-ENET/IP firmware allows remote attackers to interrupt module Ethernet communication. The Ethernet port accepts specially crafted SLMP packets without correctly validating their specified input type, leaving communication in a denial-of-service state. No authentication or user action is required, and restoring communication requires a module reset.

The record

CVE
CVE-2024-8403
Published
Nov 19, 2024
Updated
Mar 31, 2026
Vendor
Mitsubishi Electric Corporation
Product
MELSEC iQ-F Series FX5-ENET/IP
Classifications
CWE-1287, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 19, 2024CVE publishedPublication date reported by the CVE source.
  2. Mar 31, 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?

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

  1. Affected versionversion=1.100 <=1.104
  2. Affected versionversion=1.100 to 1.104

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5-ENET/IPversion=1.100 <=1.104; version=1.100 to 1.104
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5-ENETversion=1.100 <=*; version=1.100 to 1.200

Published CVSS scores

7.5Mitsubishi Electric CorporationCVSS: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

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1287Improper Validation of Specified Type of Input
T0814Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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