Overview
BIGLOBE mail addresses and IDs of 5,016,432 people leaked, including passwords of 4,631,775 (a subset). This stems from the intrusion into KDDI's mail platform for ISPs (recorded separately); the figure is a subset of KDDI's total and must not be added to it.
Timeline
- Occurred
- Discovered
- Disclosed
Organization response
Per the notice, the organisation investigated and contained the incident, notified individuals and offered monitoring or protective resources.
What you can do
Be wary of emails, SMS or calls impersonating the organisation; do not open links or attachments or enter passwords or card details. Change reused passwords on other services.
Sources
- 「BIGLOBEメール」に対する不正アクセスの発生についてビッグローブ株式会社 · 2026-11-09
- 「BIGLOBEメール」に対する不正アクセスについてのお詫びとご報告ビッグローブ株式会社 · 2026-11-09