# Hitachi Energy Relion 670/650 reboot flaw requires authentication

Published: 2026-02-05 · Severity: routine · Sectors: energy, infrastructure
Canonical: https://vorant.io/reports/6a7c7adf-f086-5313-ad3c-5950b3c91ab6/hitachi-energy-relion-670-650-reboot-flaw-requires-authentication

> Authenticated FTP users can crash Hitachi Energy Relion protective relays via disk space mismanagement; no active exploitation reported.

Hitachi Energy has published a CISA advisory documenting CVE-2025-1718, a denial-of-service vulnerability affecting Relion 670/650 and SAM600-IO series protective relays used in electrical grids and power distribution worldwide. An authenticated attacker with file access privilege via FTP can trigger an improper disk space management condition that causes the device to reboot, disrupting protection and monitoring of critical infrastructure. The vulnerability arises from CWE-754 (improper check for unusual or exceptional conditions) and affects multiple firmware versions from 1.x through 2.2.6.3, with the exception of patched minor revisions.

Hitachi Energy has released patches for affected versions: Relion 670/650 2.2.6 should update to 2.2.6.4 or later; 2.2.5 (including SAM600-IO) to 2.2.5.8 or later; 2.2.4 to 2.2.4.6 or later; 2.2.1 to 2.2.1.9 or later. Alternatively, users can upgrade to version 2.2.7 or later. CISA reports no known public exploitation to date. Defenders should prioritize patching and restrict FTP access to Relion devices; network segmentation and access controls are critical given the criticality of these devices to power grid stability.

## Mentioned in this report

- Vulnerabilities: CVE-2025-1718

Source reporting: https://www.cisa.gov/news-events/ics-advisories/icsa-25-184-01

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