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OpenAdvisories
Critical ICSA-26-279-06 6 CVEs

Hitachi Energy RTU500

Published Sep 29, 2026 · Updated Oct 6, 2026 · Revision 2

Vendor: Hitachi Energy Product: RTU500 series CMU firmware

Summary

Hitachi Energy is publishing this cybersecurity advisory in response to the security findings reported by Dragos affecting end-of-life RTU500 CMU firmware version 9.x. The reported findings are associated with legacy RTU500 firmware versions that were developed according to the cybersecurity requirements, threat landscape, and industry practices that existed at the time of their release. As cybersecurity threats and security expectations have evolved, these end-of-life versions no longer incorporate many of the security controls and hardening measures that are standard in modern industrial control systems. Over successive RTU500 releases, Hitachi Energy has continuously enhanced the security of the product through the introduction of additional security features, protocol hardening, stronger authentication and access controls, encrypted communications, and other security-by-design improvements. While the findings reported by Dragos do not affect currently supported RTU500 CMU firmware versions, there is a likelihood that the end-of-life versions 11.x and prior are affected by these vulnerabilities. Since the end-of-life versions are no longer maintained with security updates, Hitachi Energy strongly recommends upgrading to a currently supported RTU500 firmware version. Customers should also implement appropriate defense-in-depth measures and cybersecurity best practices to reduce risk and strengthen the security posture of their operational environments. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation.

Vulnerabilities 6

Revision history

  1. #2

    Initial CISA Republication of Hitachi Energy PSIRT 8DBD000251 advisory

  2. #1

    Initial public release

References