[Contained][Severity: Critical][Intrusion]

JR Kyushu: unauthorized access to the group network

The JR Kyushu group companies' network was accessed by a third party on 17 October 2025. Security tools detected and blocked it, but a later investigation concluded PC login information may have leaked. It covers 14,638 current and former employees and temporary staff of 58 group companies: names, company email addresses and PC login IDs. JR Kyushu's own employees are not included. No leak had been confirmed.

Disclosed

2026-01-19

Organizations involved

Leaked or at risk

14.6K

14,638

Downtime

Unknown

Timeline

Started, Detected 2025-10-17
Disclosed 2026-01-19
94 days

Attack or cause

Method: [Intrusion]
Impact: [Data leak]
Entry point: Unknown

Data exposed or at risk

[Name][E-mail address][Passwords]

Organizations involved

[Breached][Critical]Fukuoka, Fukuoka, HakataTransport and postal services14,638 leaked
Kyushu Railway Company
Its group companies' network

						Note
Kyushu Railway Company	[Breached]	[Critical]	Fukuoka, Fukuoka, Hakata	Transport and postal services	14,638	Its group companies' network

Open in organization search

Sources

[1][Official]サイバー攻撃によるグループ会社従業員の個人情報漏えいの可能性についてJR Kyushu · 2026-01-19