CVE-2026-1874 - Vulnerability Details

- Denial-of-Service (DoS) vulnerability in Ethernet function of MELSEC iQ-F Series EtherNet/IP module and Ethernet module

Description

Always-Incorrect Control Flow Implementation vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP versions 1.106 and prior and Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-EIP EtherNet/IP Module FX5-EIP versions 1.000 and prior allows a remote attacker to cause a denial-of-service (DoS) condition on the products by continuously sending UDP packets to the products. A system reset of the product is required for recovery.

Published: 2026-03-03

Score: 8.7 High

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

An always‑incorrect control flow implementation (CWE‑670) in Mitsubishi Electric’s MELSEC iQ‑F Series FX5‑ENET/IP Ethernet Module FX5‑ENET/IP versions 1.106 and prior, and the FX5‑EIP EtherNet/IP Module FX5‑EIP versions 1.000 and prior, permits a remote attacker to trigger a denial‑of‑service condition by repeatedly sending UDP packets to the device. The continuous flood causes internal state corruption and results in a persistent DoS that can only be recovered through a system reset.

Affected Systems

The vulnerability affects Mitsubishi Electric’s MELSEC iQ‑F Series FX5‑EIP EtherNet/IP Module FX5‑EIP (all released versions) and the FX5‑ENET/IP Ethernet Module FX5‑ENET/IP versions up to and including 1.106. Network engineers must verify that any deployed devices of these models are within this version range.

Risk and Exploitability

The CVSS score of 8.7 indicates a high impact on availability, while the EPSS value of less than 1% suggests a low likelihood of exploitation. The flaw is not listed in CISA’s KEV catalog, and no authentication is required, meaning any unauthenticated actor can trigger the DoS by sending crafted UDP packets over the network.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Mitsubishi Electric Corporation

MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP

unaffected

Version	Status	Constraints
`versions 1.106 and prior`	affected	—

Mitsubishi Electric Corporation

MELSEC iQ-F Series FX5-EIP EtherNet/IP Module FX5-EIP

unaffected

Version	Status	Constraints
`versions 1.000 and prior`	affected	—

Configuration 1 [-]

AND

cpe:2.3:o:mitsubishielectric:melsec_iq-f_fx5-eip_firmware:*:*:*:*:*:*:*:*

cpe:2.3:h:mitsubishielectric:melsec_iq-f_fx5-eip:-:*:*:*:*:*:*:*

Configuration 2 [-]

AND

cpe:2.3:o:mitsubishielectric:melsec_iq-f_fx5-enet\/ip_firmware:*:*:*:*:*:*:*:*

cpe:2.3:h:mitsubishielectric:melsec_iq-f_fx5-enet\/ip:-:*:*:*:*:*:*:*

No data.

Vendor Product Confidence Versions

Mitsubishi Electric

Melsec Iq-f Series Fx5-enet/ip Ethernet Module Fx5-enet/ip

100%

Version	Status	Scheme	Platform
`[0,1.106]`	affected	generic	—

Mitsubishi Electric

Melsec Iq-f Series Fx5-enet Ip

81%

Version	Status	Scheme	Platform
`[0,*]`	affected	generic	—

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Update the firmware or software on all affected FX5‑EIP and FX5‑ENET/IP modules to the latest Mitsubishi‑Electric release that corrects the UDP handling flaw.
Configure network perimeter devices or firewalls to block unsolicited UDP traffic destined for the IP addresses of the affected modules, permitting only traffic from known, authorized control systems.
As a temporary measure, isolate the modules on a dedicated, VLAN‑segmented network segment with strict access controls, and if possible disable or rate‑limit all non‑essential UDP services until a patch is applied.

Generated by OpenCVE AI on April 28, 2026 at 17:35 UTC.

Tracking

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Advisories

No advisories yet.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.0014.

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://jvn.jp/vu/JVNVU93286687/
https://www.cisa.gov/news-events/ics-advisories/icsa-26-62-01
https://www.mitsubishielectric.com/psirt/vulnerability/pdf/2025-021_en.pdf

History

Mon, 04 May 2026 14:30:00 +0000

Type	Values Removed	Values Added
First Time appeared		Mitsubishielectric Mitsubishielectric melsec Iq-f Fx5-eip Mitsubishielectric melsec Iq-f Fx5-eip Firmware Mitsubishielectric melsec Iq-f Fx5-enet\/ip Mitsubishielectric melsec Iq-f Fx5-enet\/ip Firmware
CPEs		cpe:2.3:h:mitsubishielectric:melsec_iq-f_fx5-eip:-:::::::* cpe:2.3:h:mitsubishielectric:melsec_iq-f_fx5-enet\/ip:-:::::::* cpe:2.3:o:mitsubishielectric:melsec_iq-f_fx5-eip_firmware:::::::: cpe:2.3:o:mitsubishielectric:melsec_iq-f_fx5-enet\/ip_firmware::::::::
Vendors & Products		Mitsubishielectric Mitsubishielectric melsec Iq-f Fx5-eip Mitsubishielectric melsec Iq-f Fx5-eip Firmware Mitsubishielectric melsec Iq-f Fx5-enet\/ip Mitsubishielectric melsec Iq-f Fx5-enet\/ip Firmware
Metrics		cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}`

Fri, 24 Apr 2026 08:00:00 +0000

Type	Values Removed	Values Added
Description	Always-Incorrect Control Flow Implementation vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP versions 1.106 and prior and Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-EIP EtherNet/IP Module FX5-EIP all versions allows a remote attacker to cause a denial-of-service (DoS) condition on the products by continuously sending UDP packets to the products. A system reset of the product is required for recovery.	Always-Incorrect Control Flow Implementation vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP versions 1.106 and prior and Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-EIP EtherNet/IP Module FX5-EIP versions 1.000 and prior allows a remote attacker to cause a denial-of-service (DoS) condition on the products by continuously sending UDP packets to the products. A system reset of the product is required for recovery.

Wed, 04 Mar 2026 21:15:00 +0000

Type	Values Removed	Values Added
First Time appeared		Mitsubishi Electric Mitsubishi Electric melsec Iq-f Series Fx5-enet/ip Ethernet Module Fx5-enet/ip Mitsubishi Electric melsec Iq-f Series Fx5-enet Ip
Vendors & Products		Mitsubishi Electric Mitsubishi Electric melsec Iq-f Series Fx5-enet/ip Ethernet Module Fx5-enet/ip Mitsubishi Electric melsec Iq-f Series Fx5-enet Ip

Wed, 04 Mar 2026 08:30:00 +0000

Type	Values Removed	Values Added
References		https://www.cisa.gov/news-events/ics-advisories/icsa-26-62-01

Tue, 03 Mar 2026 15:15:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Tue, 03 Mar 2026 07:00:00 +0000

Type	Values Removed	Values Added
Description		Always-Incorrect Control Flow Implementation vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP versions 1.106 and prior and Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-EIP EtherNet/IP Module FX5-EIP all versions allows a remote attacker to cause a denial-of-service (DoS) condition on the products by continuously sending UDP packets to the products. A system reset of the product is required for recovery.
Title		Denial-of-Service (DoS) vulnerability in Ethernet function of MELSEC iQ-F Series EtherNet/IP module and Ethernet module
Weaknesses		CWE-670
References		https://jvn.jp/vu/JVNVU93286687/ https://www.mitsubishielectric.com/psirt/vulnerability/pdf/2025-021_en.pdf
Metrics		cvssV4_0 `{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}`

Subscriptions

Mitsubishi Electric Melsec Iq-f Series Fx5-enet/ip Ethernet Module Fx5-enet/ip Melsec Iq-f Series Fx5-enet Ip

Mitsubishielectric Melsec Iq-f Fx5-eip Melsec Iq-f Fx5-eip Firmware Melsec Iq-f Fx5-enet\/ip Melsec Iq-f Fx5-enet\/ip Firmware

MITRE

Status: PUBLISHED

Assigner: Mitsubishi

Published: 2026-03-03T06:46:21.526Z

Updated: 2026-04-24T07:24:38.061Z

Reserved: 2026-02-04T04:08:41.166Z

Link: CVE-2026-1874

Vulnrichment

Updated: 2026-03-03T14:35:36.790Z

NVD

Status : Analyzed

Published: 2026-03-03T07:16:10.067

Modified: 2026-05-04T14:27:25.257

Link: CVE-2026-1874

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-04-28T17:45:16Z

Weaknesses

CWE-670

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Exploitation none

Automatable yes

Technical Impact partial

Subscriptions

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