dbcve.org
Melsec Iq F Fx5 Eip FirmwareOperating system · Mitsubishielectric

CVE-2026-1875

HIGH · 7.5 CVSS v3.1 Published 2026-03-03
Fix available
A fix is available. Upgrade to after 1.000 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Improper Resource Shutdown or Release vulnerability in 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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The FX5-EIP EtherNet/IP module versions 1.000 and prior contains an improper resource shutdown or release vulnerability where continuously sending UDP packets to the device exhausts internal resources (likely memory or network buffers) causing a denial-of-service condition that requires a system reset to recover.

MitigationImplement network segmentation and firewall rules to restrict UDP traffic to the device, and apply vendor-supplied firmware updates when available. Consider implementing rate-limiting on UDP traffic to the affected module.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Melsec Iq F Fx5 Eip FirmwareOperating system
Affected:<= 1.000

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify FX5-EIP module in your environment
    Locate any Mitsubishi Electric Melsec iQ-F series PLC or controller with the FX5-EIP EtherNet/IP communication module installed. Check physical hardware labels or review device inventory for 'FX5-EIP' or 'Melsec iQ-F' entries.
    Affected if The FX5-EIP module is present in your environment
  2. Check FX5-EIP firmware version
    Access the module configuration via Mitsubishi GX Works3 software or the device web interface. Navigate to the EtherNet/IP module settings and locate the firmware version field. Compare the version number to 1.000.
    Affected if The firmware version is 1.000 or lower
  3. Verify UDP communication is enabled
    In GX Works3, open the FX5-EIP module parameters. Check the UDP settings under the EtherNet/IP configuration. Confirm whether UDP communication ports (typically UDP port 2222 for EIP) are configured as active.
    Affected if UDP is enabled and the module is configured for EtherNet/IP communication
  4. Check network accessibility of the module
    Use network scanning tools (such as nmap) to send UDP probes to the device IP address on common EtherNet/IP UDP ports. Verify if the device responds or accepts UDP traffic from your network segment.
    Affected if The module is reachable via UDP from your network and responds to UDP probes

You are affected if you have a FX5-EIP module with firmware version 1.000 or lower that has UDP communication enabled and is network-accessible.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 1.000
Interim mitigation

Implement network segmentation and firewall rules to restrict UDP traffic to the device, and apply vendor-supplied firmware updates when available. Consider implementing rate-limiting on UDP traffic to the affected module.

Recommended fix Moderate confidence

FX5-EIP firmware version > 1.000 (contact Mitsubishi for exact fixed release number)

  1. Identify the current firmware version of the FX5-EIP EtherNet/IP module by accessing the module's configuration or system information
  2. Download the latest firmware version from the official Mitsubishi Electric support website (www.mitsubishielectric.com) - look for FX5-EIP firmware updates that address this vulnerability
  3. Follow the standard firmware update procedure documented in the MELSEC iQ-F Series manual - this typically involves using Mitsubishi's configuration software (GX Works3 or similar)
  4. Upload the new firmware to the FX5-EIP module
  5. After firmware update, verify the new version is installed and confirm the vulnerability is remediated
  6. Test normal operations to ensure the module functions correctly after the update
  7. Document the firmware version update for audit and compliance purposes
Caveat Standard firmware update procedure carries minimal risk but should be performed during planned maintenance window as the module may require restart

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Melsec Iq F Fx5 Eip Firmware Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,280
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-1875 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-1875 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data