Kyushu Electric Power Data Breach History

This page tracks the Kyushu Electric Power data breach history and cybersecurity incidents affecting Kyushu Electric Power (Japan). BreachHistory currently indexes 2 publicly disclosed or catalogued incidents spanning 2024 through 2026, with approximately 11.3 million records reported as exposed across all indexed events. These totals may include overlapping datasets or third-party estimates and should not be interpreted as unique affected users.

The Kyushu Electric Power breach timeline includes major data breaches, cyber attacks, data leaks, credential exposures, API abuse, and other security incidents. Each incident provides details on the estimated records exposed, attack method, affected data types, and supporting public sources. Currently, 0 incidents are company-confirmed.

Largest Kyushu Electric Power Data Breaches

The largest indexed incidents include the 2026 Kyushu Electric Power — lost unencrypted backup SSD; up to 10.9M customer acc… and the 2024 Kyuhen (Kyuden affiliate) ransomware — up to ~374k customer records potential…. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by Kyushu Electric Power or a regulator. Below is the list of large data breaches:

• 2026 2026 Kyushu Electric Power — lost unencrypted backup SSD; up to 10.9M customer accounts — about 10.9M records exposed · Catalogued incident
• 2024 2024 Kyuhen (Kyuden affiliate) ransomware — up to ~374k customer records potentially exposed — about 374.0K records exposed · Catalogued incident

What Information Was Exposed?

Depending on the incident, exposed data may include phone numbers, names, physical addresses, payment card and financial account data, bank account details, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.

Kyushu Electric Power Data Breach 2026

At the time of this update, BreachHistory catalogues 1 2026 incident related to Kyushu Electric Power. Most recent entry: 2026 Kyushu Electric Power — lost unencrypted backup SSD; up to 10.9M customer accounts. New incidents are added as official disclosures, regulatory filings, or credible cybersecurity reports become available.

What To Do If You Were Affected

If you believe your account may have been involved in a Kyushu Electric Power data breach, change any reused passwords, enable multi-factor authentication (MFA), monitor your account for suspicious activity, and be cautious of phishing emails or fake breach notifications.

This Kyushu Electric Power breach history is maintained by BreachHistory using public disclosures, regulatory filings, security research, and clearly labelled third-party claims. For the complete breach timeline, records exposed, incident details, and AI Breach Risk Score, explore the sections on this page.