日本郵便（JP Business Tool Box）Data breach / unauthorized access incident
- Occurred on
- Unconfirmed
- Announced on
- October 13, 2026
- Severity
- BIncidents centered on names and contact details.
- Scale
- 4,807 records
- Main impact
- Due to a defect in 法人向けJP Business Tool Box for corporate users, sender information on shipping labels was viewable by other users. Up to 4,807 records were affected, and no evidence of download or use has been found.
- Information involved
- Email addressPhone numberHome addressFull name
- Cause / key point
- An application defect caused label sender information to be viewable by other users.
- 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.
- 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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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
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Attack method classification: Misconfiguration & access-control gaps(Data left readable by anyone)
Read the Misconfiguration & access-control gaps guide and national trends →