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

published 2026-03-03 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-9282

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits: 0; none known

Improper Resource Shutdown or Release vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP 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.

Vendor advisories

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

cisa ICSA-26-062-01 updated 2026-05-07 cvss 7.5

Mitsubishi Electric MELSEC iQ-F Series EtherNet/IP module and Ethernet Module (Update A)

Mitsubishi Electric MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP
affected: mitigation, no fix planned

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 8 mo ago (2026-03-03)

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.7	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
CNA	4.0	8.7	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP

Classification

Weakness

CWE-404 Improper Resource Shutdown or Release

References

mitsubishielectric.com /psirt/vulnerability/pdf/2025-021_en.pdf
vendor-advisory
jvn.jp /vu/JVNVU93286687/
government-resource, third-party-advisory
cisa.gov /news-events/ics-advisories/icsa-26-62-01
government-resource, third-party-advisory

Sources

CVE List CVE-2026-1876
NVD CVE-2026-1876

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary