CISA 2026-06-18

Mitsubishi Electric Co.'s MELSEC iQ-F Series FX5-ENET/IP Ethernet Module

CVE-2026-8806

Machine-generated analysis · WAYSCloud LLM

The advisory states that all versions of the FX5-ENET/IP module are affected by a DoS vulnerability due to excessive packet processing. No fix is planned for this product.

Context

The affected product is Mitsubishi Electric's MELSEC iQ-F Series FX5-ENET/IP Ethernet Module, used in industrial automation systems. The advisory describes a vulnerability where sending a high volume of packets to the Ethernet port can trigger a denial-of-service condition by overwhelming processing and halting communication functions. This issue is categorized as an Expected Behavior Violation (CWE-440). The vendor has stated there are no plans to release a fixed version.

Operator considerations

Check: Determine if FX5-ENET/IP modules are present in the environment.
Isolate: Restrict network access to the module's Ethernet port to prevent excessive traffic.
Patch: No fix is planned; mitigation through network controls is recommended.
Log: Monitor network traffic to the module for unusual packet volumes that may indicate exploitation attempts.

From Cybersecurity and Infrastructure Security Agency ↗

Successful exploitation of this vulnerability could allow a remote attacker to cause a denial-of-service (DoS) condition in the affected product by continuously sending a large number of communication packets to the Ethernet port of the product in a short period of time, increasing the processing load of the product, preventing the internal anomaly-detection processing from being performed, and causing the communication function to stop.

The following versions of Mitsubishi Electric Co.'s MELSEC iQ-F Series FX5-ENET/IP Ethernet Module are affected:

Mitsubishi Electric MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP vers:all/* (CVE-2026-8806)

Vendor

Equipment

Mitsubishi Electric

Mitsubishi Electric Co.'s MELSEC iQ-F Series FX5-ENET/IP Ethernet Module

Expected Behavior Violation

Critical Infrastructure Sectors: Critical Manufacturing

Countries/Areas Deployed: Worldwi...

Read the full advisory on CISA →