Mitsubishi CC-Link IE TSN protocol flaw enables DoS

A message integrity flaw in Mitsubishi Electric's CC-Link IE TSN protocol lets a network-adjacent attacker tamper with control traffic and cause denial-of-service across dozens of industrial products.

CISA republished a Mitsubishi Electric advisory (2026-005) describing CVE-2026-13584, an improper message integrity enforcement vulnerability (CWE-924) in the CC-Link IE TSN communication protocol used across a very broad range of Mitsubishi Electric industrial automation hardware and software, including MELSEC MX controllers, master/local modules, motion modules, remote I/O modules, AC servos, inverters, industrial robots, GOT3000 HMIs, and related SDKs and software packages.

An attacker with access to the same network segment could send specially crafted packets under specific timing conditions to tamper with control input/output data, potentially disrupting control functions or causing devices to behave incorrectly, resulting in a denial-of-service condition. No fix is currently planned; Mitsubishi Electric instead recommends compensating controls such as restricting physical access to devices and network segments, locking control panels and Ethernet ports, isolating CC-Link IE TSN networks from untrusted networks via firewalls, and enforcing strong access control at network boundaries.

The vulnerability was responsibly disclosed by researchers at Nozomi Networks. Given the scale of affected products (over 100 models spanning controllers, servos, robots, HMIs, and industrial computers) primarily deployed in Critical Manufacturing environments worldwide, organizations using CC-Link IE TSN should prioritize network segmentation and access restriction since no patch is forthcoming.

Source reporting: https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-07