日本郵便（郵便局アプリ）Data breach / unauthorized access incident
- Occurred on
- Unconfirmed
- Announced on
- September 29, 2026
- Severity
- AFinancial and HR records — information that easily translates into monetary damage.
- Scale
- 19 people
- Main impact
- It has been confirmed that data for 19 people — 69 items of member information, address books, shipping label information, etc. — were illicitly obtained. The specific items affected (such as family status) vary depending on the registered information.
- Information involved
- Email addressPhone numberHome addressFull nameDate of birth
- Cause / key point
- Cause is under investigation.
- Industry
- Transport & travel
- Listing / capital
- UnlistedParent company.: 日本郵政(東証プライム 6178)
日本郵便 is a subsidiary of 日本郵政.
- Sources
- Last updated
- October 20, 2026
Stock price reaction to the disclosure日本郵政・親会社 / 東証プライム 6178
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CEO of MediaLeap Inc. Working on both sides of web advertising and web media since 2013; founded the company in May 2025.
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Attack method classification: Under investigation / not stated(Cause not disclosed)
Read the Under investigation / not stated guide and national trends →