> JapanHacked_
[Contained][Severity: Major][Intrusion]

Japan Post: unauthorized access to the Post Office App

The Japan Post app run by Japan Post Holdings and Japan Post was accessed from outside, and Yu ID and the app went into emergency maintenance at about 22:30 on 25 September. Service resumed on 26 September after investigation and fixes. 69 customer records (19 people) were taken, including Yu ID member data, address book entries and shipping labels created in the app.

Disclosed

2026-09-29

Organizations involved

1

Leaked or at risk

69

69

Downtime

Unknown

Timeline

  1. Detected 2026-09-25
  2. Disclosed 2026-09-29
  3. 4 days

Attack or cause

Method
[Intrusion]
Impact
[Data leak][Service outage]
Entry point
Unknown

Data exposed or at risk

[Name][Postal address][Date of birth][Gender][Phone number][E-mail address][Employment]

Services hit

Organizations involved

Open in organization search

Sources

  1. [1][Official]郵便局アプリへの不正アクセスについてJapan Post Holdings and Japan Post · 2026-09-29
  2. [2][News]「郵便局アプリ」に不正アクセス　氏名や送り先住所など漏えい　19人分・69件ITmedia NEWS · 2026-09-30