Hitachi Energy RTU500 Product

View CSAF Summary Hitachi Energy is aware of vulnerabilities that affect RTU500 product versions listed in this document. Successful exploitation of these vulnerabilities can result in the exposure of low-value user management information and device outage. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation. The following versions of Hitachi Energy RTU500 Product are affected: RTU500 series CMU Firmware vers:RTU500_series_CMU_Firmware/>=12.7.1|<=12.7.7, vers:RTU500_series_CMU_Firmware/>=13.5.1|<=13.5.4, vers:RTU500_series_CMU_Firmware/>=13.6.1|<=13.6.2, vers:RTU500_series_CMU_Firmware/>=13.7.1|<=13.7.7, 13.8.1  CVSS Vendor Equipment Vulnerabilities

v3 7.5 Hitachi Energy Hitachi Energy RTU500 Product Improper Handling of Insufficient Permissions or Privileges , Incomplete List of Disallowed Inputs, Uncontrolled Recursion, Allocation of Resources Without Limits or Throttling

Background Critical Infrastructure Sectors: Critical Manufacturing Countries/Areas Deployed: Worldwide Company Headquarters Location: Switzerland Vulnerabilities Expand All + CVE-2026-1772 RTU500 web interface: An unprivileged user can read user management information. The information cannot be accessed via the RTU500 web user interface but requires further tools like browser development utilities to access them without required privileges. View CVE Details Affected Products Hitachi Energy RTU500 Product Vendor: Hitachi Energy Product Version: RTU500 series CMU Firmware version 12.7.1 through 12.7.7, RTU500 series CMU Firmware version 13.5.1 through 13.5.4, RTU500 series CMU Firmware version 13.6.1 through 13.6.2, RTU500 series CMU Firmware version 13.7.1 through 13.7.7, RTU500 series CMU Firmware version 13.8.1 Product Status: known_affected Remediations Vendor fix Update to CMU Firmware version 12.7.8 Mitigation Follow general mitigation factors/workarounds Vendor fix Update to CMU Firmware version 13.7.8 or latest Vendor fix Update to CMU Firmware version 13.8.2 Relevant CWE: CWE-280 Improper Handling of Insufficient Permissions or Privileges Metrics CVSS Version Base Score Base Severity Vector String

3.1 4.3 MEDIUM CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVE-2026-1773 IEC 60870-5-104: Potential Denial of Service impact on reception of invalid U-format frame. Product is only affected if IEC 60870-5-104 bi-directional functionality is configured. Enabling secure communication following IEC 62351-3 does not remediate the vulnerability but mitigates the risk of exploitation. View CVE Details Affected Products Hitachi Energy RTU500 Product Vendor: Hitachi Energy Product Version: RTU500 series CMU Firmware version 12.7.1 through 12.7.7, RTU500 series CMU Firmware version 13.5.1 through 13.5.4, RTU500 series CMU Firmware version 13.6.1 through 13.6.2, RTU500 series CMU Firmware version 13.7.1 through 13.7.7, RTU500 series CMU Firmware version 13.8.1 Product Status: known_affected Remediations Vendor fix Update to CMU Firmware version 12.7.8 Mitigation Follow general mitigation factors/workarounds Vendor fix Update to CMU Firmware version 13.7.8 or latest Vendor fix Update to CMU Firmware version 13.8.2 Relevant CWE: CWE-184 Incomplete List of Disallowed Inputs Metrics CVSS Version Base Score Base Severity Vector String

3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVE-2024-8176 A stack overflow vulnerability exists in the libexpat library due to the way it handles recursive entity expansion in XML documents. When parsing an XML document with deeply nested entity references, libexpat can be forced to recurse indefinitely, exhausting the stack space and causing a crash. This issue could lead to denial of service (DoS) or, in some cases, exploitable memory corruption, depending on the environment and library usage. Product is only affected if IEC61850 functionality is configured. View CVE Details Affected Products Hitachi Energy RTU500 Product Vendor: Hitachi Energy Product Version: RTU500 series CMU Firmware version 12.7.1 through 12.7.7, RTU500 series CMU Firmware version 13.5.1 through 13.5.4, RTU500 series CMU Firmware version 13.6.1 through 13.6.2, RTU500 series CMU Firmware version 13.7.1 through 13.7.7, RTU500 series CMU Firmware version 13.8.1 Product Status: known_affected Remediations Vendor fix Update to CMU Firmware version 12.7.8 Mitigation Follow general mitigation factors/workarounds Vendor fix Update to CMU Firmware version 13.7.8 or latest Vendor fix Update to CMU Firmware version 13.8.2 Relevant CWE: CWE-674 Uncontrolled Recursion Metrics CVSS Version Base Score Base Severity Vector String

3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVE-2025-59375 libexpat in Expat before 2.7.2 allows attackers to trigger large dynamic memory allocations via a small document that is submitted for parsing. Product is only affected if IEC61850 functionality is configured. View CVE Details Affected Products Hitachi Energy RTU500 Product Vendor: Hitachi Energy Product Version: RTU500 series CMU Firmware version 12.7.1 through 12.7.7, RTU500 series CMU Firmware version 13.5.1 through 13.5.4, RTU500 series CMU Firmware version 13.6.1 through 13.6.2, RTU500 series CMU Firmware version 13.7.1 through 13.7.7, RTU500 series CMU Firmware version 13.8.1 Product Status: known_affected Remediations Vendor fix Update to CMU Firmware version 12.7.8 Mitigation Follow general mitigation factors/workarounds Vendor fix Update to CMU Firmware version 13.7.8 or latest Vendor fix Update to CMU Firmware version 13.8.2 Relevant CWE: CWE-770 Allocation of Resources Without Limits or Throttling Metrics CVSS Version Base Score Base Severity Vector String

3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Acknowledgments Hitachi Energy PSIRT reported these vulnerabilities to CISA. Notice The information in this document is subject to change without notice and should not be construed as a commitment by Hitachi Energy. Hitachi Energy provides no warranty, express or implied, including warranties of merchantability and fitness for a particular purpose, for the information contained in this document, and assumes no responsibility for any errors that may appear in this document. In no event shall Hitachi Energy or any of its suppliers be liable for direct, indirect, special, incidental or consequential damages of any nature or kind arising from the use of this document, or from the use of any hardware or software described in this document, even if Hitachi Energy or its suppliers have been advised of the possibility of such damages. This document and parts hereof must not be reproduced or copied without written permission from Hitachi Energy and the contents hereof must not be imparted to a third party nor used for any unauthorized purpose. All rights to registrations and trademarks reside with their respective owners. Support For additional information and support please contact your product provider or Hitachi Energy service organization. For contact information, see https://www.hitachienergy.com/contact-us/ for Hitachi Energy contact-centers. General Mitigation Factors Recommended security practices and firewall configurations can help protect a process control network from attacks that originate from outside the network. Such practices include that process control systems are physically protected from direct access by unauthorized personnel, have no direct connections to the Internet, and are separated from other networks by means of a firewall system that has a minimal number of ports exposed, and others that have to be evaluated case by case. Process control systems should not be used for Internet surfing, instant messaging, or receiving e-mails. Portable computers and removable storage media should be carefully scanned for viruses before they are connected to a control system. Proper password policies and processes should be followed. Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the exploitation risk of this vulnerability. Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolate them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most recent version available. Also recognize VPN is only as secure as its connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. Advisory Conversion Disclaimer This ICSA is a verbatim republication of Hitachi Energy PSIRT 8DBD000237 from a direct conversion of the vendor's Common Security Advisory Framework (CSAF) advisory. This is republished to CISA's website as a means of increasing visibility and is provided "as-is" for informational purposes only. CISA is not responsible for the editorial or technical accuracy of republished advisories and provides no warranties of any kind regarding any information contained within this advisory. Further, CISA does not endorse any commercial product or service. Please contact Hitachi Energy PSIRT directly for any questions regarding this advisory. Revision History Initial Release Date: 2026-02-24 Date Revision Summary

2026-02-24 1 Initial public release

2026-03-03 2 Initial CISA Republication of Hitachi Energy PSIRT 8DBD000237 advisory

Legal Notice and Terms of Use

Source: CISA Alerts