東京メトロ（メトポ）Data breach / unauthorized access incident
- Occurred on
- Unconfirmed
- Announced on
- September 27, 2026
- Severity
- BIncidents centered on names and contact details.
- Scale
- 59,000 records
- Main impact
- Approximately 59,000 email addresses for which delivery had been stopped may have been viewed or obtained. The affected server is reported to contain no member information other than email addresses.
- Information involved
- Email address
- Cause / key point
- Unauthorized access to the server that stores delivery-stopped email addresses. The detailed cause is under investigation.
- Industry
- Transport & travel
- Listing / capital
- Listed company東証プライム 9023(東京地下鉄)
- Last updated
- October 20, 2026
Stock price reaction to the disclosure東京地下鉄 / 東証プライム 9023
Stock information is reference data based on Yahoo Finance and may be delayed. This site does not solicit or advise investment and does not guarantee the accuracy or completeness of this information. We accept no liability for any investment decision based on it.
Is this incident worth paying attention to?
Written & reviewed
Reviewed byYutaro SasaoFounder & CEO, MediaLeap Inc.
CEO of MediaLeap Inc. Working on both sides of web advertising and web media since 2013; founded the company in May 2025.
Review scope: cross-checking against primary sources (official and government announcements), verifying claims stay within the facts, and checking source attribution。Last reviewed:
Written by:Leak Watch editorial team (AI-assisted drafts verified against sources by the editorial team) · Reviewer profile · Request a correction
Related incidents
Browse the database →Incidents sharing the same company, service, attack method or industry (grouped automatically from the disclosures).
Same attack method
- SSソースネクスト2026.10.15 announced・Affected 22,519,960 records
- SSバーガーキング・ジャパン(公式アプリ)2026.10.15 announced・Affected 11,180,000 records
- SS焼肉きんぐ2026.10.05 announced・Affected 10,788,963 records
- Bユミルリンク（メール配信システム）2026.10.19 announced・Affected 9,000,000 records
- SSタイムズカー(タイムズモビリティ)2026.09.25 announced・Affected 6,600,000 accounts
- Sブックオフグループ(ブックオフコーポレーション)2026.10.09 announced・Affected 6,383,279 people
Same industry
- SSSアドベンチャー（スカイチケット）2026.10.10 announced・Affected 14,640,000 records
- S日水物流(ニッスイグループ)2026.10.07 announced・Affected Unknown
- Sあいの風とやま鉄道株式会社2026.09.15 announced・Affected 1,409 people
- S西武鉄道（52席の至福）2026.09.02 announced・Affected 500 people
- Aエイチ・アイ・エス(HIS タイ現地法人)2026.10.07 announced・Affected 627 people
- A佐川急便（お荷物問い合わせ）2026.10.01 announced・Affected Unknown
Attack method classification: Unauthorized access (method undisclosed)(Breached, but the technique was not identified or disclosed)
Read the Unauthorized access (method undisclosed) guide and national trends →