Summary
Hitachi Energy is aware of vulnerabilities that affect RTU500 product versions listed in this document. If exploited, these vulnerabilities primarily impact product availability, with potential secondary impacts on confidentiality and integrity. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation.
The following versions of Hitachi Energy RTU500 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|<=13.6.3, vers:RTU500_series_CMU_Firmware/>=13.7.1|<=13.7.8, 13.8.1, vers:RTU500_series_CMU_Firmware/>=13.7.1|<=13.7.7 (CVE-2025-69421, CVE-2026-24515, CVE-2026-25210, CVE-2026-32776, CVE-2026-32777, CVE-2026-32778, CVE-2026-8479, CVE-2025-69421, CVE-2026-24515, CVE-2026-25210, CVE-2026-32776, CVE-2026-32777, CVE-2026-32778, CVE-2026-8479, CVE-2025-69421, CVE-2026-24515, CVE-2026-25210, CVE-2026-32776, CVE-2026-32777, CVE-2026-32778, CVE-2026-8479, CVE-2025-69421, CVE-2026-24515, CVE-2026-25210, CVE-2026-32776, CVE-2026-32777, CVE-2026-32778, CVE-2025-69421, CVE-2026-24515, CVE-2026-25210, CVE-2026-32776, CVE-2026-32777, CVE-2026-32778, CVE-2026-8479, CVE-2026-8479)
| CVSS | Vendor | Equipment | Vulnerabilities |
|---|---|---|---|
| v3 7.8 | Hitachi Energy | Hitachi Energy RTU500 | NULL Pointer Dereference, Integer Overflow or Wraparound, Loop with Unreachable Exit Condition (‘Infinite Loop’) |
Background
- Critical Infrastructure Sectors: Dams, Energy, Water and Wastewater
- Countries/Areas Deployed: Worldwide
- Company Headquarters Location: Switzerland
Vulnerabilities
CVE-2025-69421
CWE-476: NULL Pointer Dereference. Issue summary: Processing a malformed PKCS#12 file can trigger a NULL pointer dereference in the PKCS12_item_decrypt_d2i_ex() function. Impact summary: A NULL pointer dereference can trigger a crash which leads to Denial of Service for an application processing PKCS#12 files. The PKCS12_item_decrypt_d2i_ex() function does not check whether the oct parameter is NULL before dereferencing it. When called from PKCS12_unpack_p7encdata() with a malformed PKCS#12 file, this parameter can be NULL, causing Denial of Service impact. The vulnerability is limited to Denial of Service and cannot be escalated to achieve code execution or memory disclosure. Product is affected, if a privileged user uploads a malformed PKCS#12 certificate via web interface or if PKI client functionality is configured.
Affected Products
Hitachi Energy RTU500
Vendor:
Hitachi Energy
Product Version:
RTU500 series CMU Firmware version 12.7.1 – 12.7.7, RTU500 series CMU Firmware version 13.5.1 – 13.5.4, RTU500 series CMU Firmware version 13.6.1 – 13.6.3, RTU500 series CMU Firmware version 13.7.1 – 13.7.8, RTU500 series CMU Firmware version 13.8.1
Product Status:
known_affected
Relevant CWE: CWE-476 NULL Pointer Dereference
Metrics
CVE-2026-24515
CWE-476: NULL Pointer Dereference. In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data, causing Denial of Service impact. Product is only affected if IEC 61850 functionality is configured.
Affected Products
Hitachi Energy RTU500
Vendor:
Hitachi Energy
Product Version:
RTU500 series CMU Firmware version 12.7.1 – 12.7.7, RTU500 series CMU Firmware version 13.5.1 – 13.5.4, RTU500 series CMU Firmware version 13.6.1 – 13.6.3, RTU500 series CMU Firmware version 13.7.1 – 13.7.8, RTU500 series CMU Firmware version 13.8.1
Product Status:
known_affected
Relevant CWE: CWE-476 NULL Pointer Dereference
Metrics
CVE-2026-25210
CWE-190: Integer Overflow or Wraparound. In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation, primarily causing Denial of Service and potentially confidentiality and integrity impact to the product. Product is only affected if IEC 61850 functionality is configured.
Affected Products
Hitachi Energy RTU500
Vendor:
Hitachi Energy
Product Version:
RTU500 series CMU Firmware version 12.7.1 – 12.7.7, RTU500 series CMU Firmware version 13.5.1 – 13.5.4, RTU500 series CMU Firmware version 13.6.1 – 13.6.3, RTU500 series CMU Firmware version 13.7.1 – 13.7.8, RTU500 series CMU Firmware version 13.8.1
Product Status:
known_affected
Relevant CWE: CWE-190 Integer Overflow or Wraparound
Metrics
CVE-2026-32776
CWE-476: NULL Pointer Dereference. libexpat before 2.7.5 allows a NULL pointer dereference with empty external parameter entity content, causing Denial of Service impact. Product is only affected if IEC 61850 functionality is configured.
Affected Products
Hitachi Energy RTU500
Vendor:
Hitachi Energy
Product Version:
RTU500 series CMU Firmware version 12.7.1 – 12.7.7, RTU500 series CMU Firmware version 13.5.1 – 13.5.4, RTU500 series CMU Firmware version 13.6.1 – 13.6.3, RTU500 series CMU Firmware version 13.7.1 – 13.7.8, RTU500 series CMU Firmware version 13.8.1
Product Status:
known_affected
Relevant CWE: CWE-476 NULL Pointer Dereference
Metrics
CVE-2026-32777
CWE-835: Loop with Unreachable Exit Condition (‘Infinite Loop’). libexpat before 2.7.5 allows an infinite loop while parsing DTD content, causing Denial of Service impact. Product is only affected if IEC 61850 functionality is configured.
Affected Products
Hitachi Energy RTU500
Vendor:
Hitachi Energy
Product Version:
RTU500 series CMU Firmware version 12.7.1 – 12.7.7, RTU500 series CMU Firmware version 13.5.1 – 13.5.4, RTU500 series CMU Firmware version 13.6.1 – 13.6.3, RTU500 series CMU Firmware version 13.7.1 – 13.7.8, RTU500 series CMU Firmware version 13.8.1
Product Status:
known_affected
Relevant CWE: CWE-835 Loop with Unreachable Exit Condition (‘Infinite Loop’)
Metrics
CVE-2026-32778
CWE-476: NULL Pointer Dereference. libexpat before 2.7.5 allows a NULL pointer dereference in the function setContext on retry after an earlier out-of-memory condition, causing Denial of Service impact. Product is only affected if IEC 61850 functionality is configured.
Affected Products
Hitachi Energy RTU500
Vendor:
Hitachi Energy
Product Version:
RTU500 series CMU Firmware version 12.7.1 – 12.7.7, RTU500 series CMU Firmware version 13.5.1 – 13.5.4, RTU500 series CMU Firmware version 13.6.1 – 13.6.3, RTU500 series CMU Firmware version 13.7.1 – 13.7.8, RTU500 series CMU Firmware version 13.8.1
Product Status:
known_affected
Relevant CWE: CWE-476 NULL Pointer Dereference
Metrics
CVE-2026-8479
CWE-476: NULL Pointer Dereference. IEC 60870-5-104 used in bidirectional mode is vulnerable for a NULL pointer dereferencing, if a specially crafted sequence of messages is sent for a certain time, causing Denial of Service impact. Product is only affected if IEC 60870-5-104 functionality in bidirectional mode (BCI) is configured.
Affected Products
Hitachi Energy RTU500
Vendor:
Hitachi Energy
Product Version:
RTU500 series CMU Firmware version 12.7.1 – 12.7.7, RTU500 series CMU Firmware version 13.5.1 – 13.5.4, RTU500 series CMU Firmware version 13.6.1 – 13.6.3, RTU500 series CMU Firmware version 13.7.1 – 13.7.7, RTU500 series CMU Firmware version 13.8.1
Product Status:
known_affected
Relevant CWE: CWE-476 NULL Pointer Dereference
Metrics
Acknowledgments
- Hitachi Energy Internal Team reported this vulnerability 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. Additional information on Industrial Control Systems Cybersecurity Best Practices can be found in the following Hitachi Energy Cybersecurity Notification. Cybersecurity Advisory – Industrial Control Systems Cybersecurity Best Practices
SSVC
SSVCv2/E:N/A:N/2026-05-26T08:50:36Z/
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 8DBD000252 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: 2026-05-26
| Date | Revision | Summary |
|---|---|---|
| 2026-05-26 | 1 | Initial public release |
| 2026-06-04 | 2 | Initial CISA Republication of Hitachi Energy PSIRT 8DBD000252 advisory |
