# CVE-2026-1874 — Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP

> As of 2026-04-24, CVE-2026-1874 is a High-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in Mitsubishi Electric Corporation MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP, CVSS v4.0 8.7, EPSS 0.4% (35.1th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-1874, most recently “Mitsubishi Electric MELSEC iQ-F FX5-ENET/IP and FX5-EIP remote unauthenticated denial-of-service via UDP flood (CVE-2026-1874, CVE-2026-1875, CVE-2026-1876)”.

**Last updated:** 2026-04-24

## What is CVE-2026-1874?

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.

The record classifies CVE-2026-1874 under weakness class [CWE-670](https://cwe.mitre.org/data/definitions/670.html). 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 221 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 8.7 — High (derived from score) (`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`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 35.1% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-03-03, last modified 2026-04-24

## Is CVE-2026-1874 being exploited?

It currently carries a trending score of 14 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Mitsubishi Electric Corporation](https://intel.threadlinqs.com/vendors/mitsubishi-electric): MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP, MELSEC iQ-F Series FX5-EIP EtherNet/IP Module FX5-EIP

## How to fix CVE-2026-1874

No vendor patch reference has been recorded for CVE-2026-1874 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-1874

1 tracked threat in the Threadlinqs corpus references CVE-2026-1874, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Mitsubishi Electric MELSEC iQ-F FX5-ENET/IP and FX5-EIP remote unauthenticated denial-of-service via UDP flood (CVE-2026-1874, CVE-2026-1875, CVE-2026-1876)](https://intel.threadlinqs.com/threat/TL-2026-1874) — HIGH · 2026-08-04

## Sources

Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on 2026-10-10.

**Vendor advisory and patch**

- [mitsubishielectric.com — vendor advisory](https://www.mitsubishielectric.com/psirt/vulnerability/pdf/2025-021_en.pdf)

**Third-party advisory**

- [jvn.jp — government resource](https://jvn.jp/vu/JVNVU93286687/)
- [cisa.gov — government resource](https://www.cisa.gov/news-events/ics-advisories/icsa-26-62-01)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-1874
Full detection coverage and IOCs for threats exploiting CVE-2026-1874 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp