---
title: Command Injection and Privilege Escalation Vulnerabilities in Hitachi Energy CoreTec Control Products
description: Hitachi Energy has disclosed two vulnerabilities affecting its CoreTec4 and CoreTec5 control products, and the Cybersecurity and Infrastructure Security Agency (CISA)
---

[Advisories | 1898 & Co.](https://1898advisories.burnsmcd.com)

# [Command Injection and Privilege Escalation Vulnerabilities in Hitachi Energy CoreTec Control Products](https://1898advisories.burnsmcd.com/command-injection-and-privilege-escalation-vulnerabilities-in-hitachi-energy-coretec-control-products)

 Written by [The 1898 & Co. Team](https://1898advisories.burnsmcd.com/author/1898-co-team) | November 2, 2026

#### Security Advisory Brief

Hitachi Energy has disclosed two vulnerabilities affecting its CoreTec4 and CoreTec5 control products, and the Cybersecurity and Infrastructure Security Agency (CISA) published a corresponding Industrial Control Systems advisory, ICSA-26-302-03, on October 29, 2026. The first issue is an operating-system command injection flaw that lets an authenticated user with certain roles run arbitrary commands on the device. The second, which the vendor refers to as "Dirty Frag," is a Linux kernel memory-corruption flaw in the CoreTec5 network stack that allows a local user to escalate privileges to root. CoreTec products serve as control and protection platforms for grid power-electronics systems such as high-voltage direct current and flexible AC transmission installations, so these weaknesses sit close to equipment that regulates the flow of electricity on the transmission network.

Technically, the command injection weakness, tracked as CVE-2026-13162 with a CVSS v3.1 score of 7.5 and a CVSS v4.0 score of 7.7, resides in the configuration daemon's time-synchronization handler. When the daemon processes a timezone configuration update, it builds a shell command by concatenating user-supplied input without sanitization or validation, allowing a suitably privileged account to break out of the intended configuration action and gain full control of the device. The privilege-escalation weakness, tracked as CVE-2026-43284 with a CVSS v3.1 score of 8.8, lies in the IPsec Encapsulating Security Payload subsystem of the Linux kernel used in CoreTec5. The kernel decrypts crafted packet data into memory pages it does not own, including cached copies of privileged system binaries, so that injected code executes with root privileges the next time one of those binaries runs.

These two flaws are meaningful on their own and more serious in combination. The command injection flaw carries a CVSS v3.1 base score of 7.5 and a CVSS v4.0 base score of 7.7, while the kernel privilege-escalation flaw carries a CVSS v3.1 base score of 8.8. An attacker who first abuses the command injection weakness to gain code execution as a lower-privileged service account could then use the kernel flaw to obtain root on a CoreTec5 unit, giving complete control over a device embedded in power-system control and protection functions. Hitachi Energy states that it is aware of both vulnerabilities and has published a fixed release; there are no public reports of exploitation in the wild at this time.

#### Threats and Vulnerabilities

CVE-2026-13162, with a CVSS v3.1 score of 7.5 and a CVSS v4.0 score of 7.7, is an OS command injection vulnerability (CWE-78) in the CoreTec product's configuration daemon. The daemon's time-synchronization handler, responsible for setting the system timezone, constructs a shell command by concatenating user-supplied input without any sanitization or validation. An authenticated user holding certain roles can therefore inject additional commands into the timezone configuration update and execute arbitrary system commands with full control over the device. Because exploitation requires valid credentials and an appropriate role, the vulnerability is most dangerous where account management is weak, where roles are over-provisioned, or where an adversary has already obtained a foothold through stolen or shared credentials. This weakness affects CoreTec5 versions 3.4.0 and prior and CoreTec4 versions 3.4.0 and prior.

CVE-2026-43284, with a CVSS v3.1 score of 8.8, is a write-what-where condition (CWE-123) that Hitachi Energy identifies as "Dirty Frag." The flaw exists in the IPsec Encapsulating Security Payload (esp4) subsystem of the Linux kernel used in CoreTec5 and allows a local unprivileged user to escalate to root. When the kernel processes crafted ESP-encrypted network packets, it decrypts data directly into memory pages it does not own, including cached copies of privileged operating-system binaries; when one of those binaries is subsequently executed, the attacker's injected code runs with root privileges. Because the vulnerable ESP component is compiled into the kernel as a built-in and is present from boot, a local user can exploit it without loading any additional module. This weakness affects CoreTec5 versions 3.4.0 and prior; CoreTec4 is not listed as affected by this issue.

#### Client Impact

For organizations operating Hitachi Energy CoreTec control products, the primary operational concern is loss of control over devices that perform protection and regulation functions in high-voltage direct current and flexible AC transmission systems. An attacker who chains the command injection and kernel flaws could obtain root on a CoreTec5 unit, enabling manipulation of device configuration, disruption of control and protection logic, or the establishment of persistent access on equipment that directly influences grid stability. Even used individually, the command injection flaw hands a credentialed insider or a credential-abusing adversary arbitrary command execution, and the kernel flaw provides a reliable path from a limited foothold to full device compromise. The requirement for authentication and local or network access limits exposure somewhat, but it does not protect environments where remote engineering access, flat networks, or shared operator accounts are present.

From a compliance standpoint, operators in the North American bulk electric system must account for these vulnerabilities within their NERC CIP programs, including patch and vulnerability management under CIP-007 and configuration and change management under CIP-010, with timely assessment and documented remediation or mitigation of the applicable systems. Operators subject to other regulatory regimes, such as those aligned to IEC 62443 or national critical-infrastructure directives, face similar obligations to evaluate affected assets and apply the vendor's fixed release or compensating controls. Failure to track and remediate vulnerabilities in grid control and protection equipment carries both regulatory exposure and the potential for service disruption that could affect customers and interconnected systems.

#### Mitigations

Hitachi Energy has published a fixed release and a set of recommended actions. Organizations should take the following steps to reduce exposure:

1. Update CoreTec5 to version 5.0.0, which remediates both CVE-2026-13162 and CVE-2026-43284; CoreTec5 versions 3.4.0 and prior should be upgraded as a priority.
2. For CoreTec4 versions 3.4.0 and prior, which are affected by the command injection flaw and for which no fixed version is currently published, apply the vendor's general mitigation factors and plan a migration path with Hitachi Energy, treating network and account controls as the primary defense in the interim.
3. Restrict and review account roles so that only required personnel hold configuration privileges, enforce least privilege, remove shared or over-provisioned accounts, and apply strong authentication to limit who can reach the configuration daemon that the command injection flaw depends on.
4. Segment CoreTec devices onto dedicated control networks isolated from business systems and the internet, limit engineering and remote access to defined jump hosts and controlled pathways, and block untrusted traffic from reaching the device network stack that the kernel flaw exploits.
5. Follow Hitachi Energy's published industrial control systems cybersecurity guidance and monitor affected devices for anomalous configuration changes, unexpected command execution, and signs of privilege escalation while remediation is scheduled.

Applying these actions in combination reduces both the likelihood that an attacker can reach the affected components and the impact if a single control is bypassed.

#### 1898 & Co. Response

1898 & Co. works alongside electric utilities and other critical-infrastructure operators to manage vulnerabilities in operational technology environments where control and protection equipment such as Hitachi Energy CoreTec is deployed. Our team has experience supporting asset owners through vulnerability triage, patch planning, and the application of compensating controls when a fixed release cannot be deployed immediately, helping reduce exposure without compromising operational continuity.

For organizations evaluating their exposure to these vulnerabilities, 1898 & Co. provides OT-focused assessment and threat-hunting services that help identify affected CoreTec assets, review account and role configurations, and validate network segmentation around grid control systems. We help operators align remediation activities with NERC CIP and other regulatory obligations so that assessment and mitigation are documented and defensible.

Through managed security services and incident response support, 1898 & Co. helps clients monitor OT networks for the configuration changes, command execution, and privilege-escalation behavior associated with these weaknesses. Our approach is designed to give asset owners earlier visibility into suspicious activity on control-system devices and a structured path to containment and recovery should an incident occur.

#### Sources

1. [Hitachi Energy Cybersecurity Advisory — Command Injection and Dirty Frag Vulnerabilities in Hitachi Energy CoreTec Product](https://publisher.hitachienergy.com/preview?DocumentID=8DBD000258&LanguageCode=en&DocumentPartId=&Action=launch)
2. [CISA ICS Advisory ICSA-26-302-03 — Hitachi Energy CoreTec Product](https://www.cisa.gov/news-events/ics-advisories/icsa-26-302-03)
3. [NVD Entry — CVE-2026-13162](https://nvd.nist.gov/vuln/detail/CVE-2026-13162)
4. [NVD Entry — CVE-2026-43284](https://nvd.nist.gov/vuln/detail/CVE-2026-43284)

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