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

Ministry of Agriculture, Forestry and Fisheries: withholding slip data sent to a wrong email address put My Numbers and other data of 4,571 staff and family members on an outside mail server

A wrong submission address for 2025 payroll tax data sent names, My Numbers and other details of 4,571 staff and family members to an external mail server.

Disclosed

2026-01-23

Organizations involved

1

Leaked or at risk

4.6K

4,571

Downtime

Unknown

What happened

  1. It found that when it was consolidating withholding slip data within the ministry, a wrong submission address had been given and the data had gone to an external mail server. [1]

  2. It announced the leak of staff personal information. [1] [2]

Impact

The leaked data covers names, dates of birth, addresses, My Numbers, salary amounts, withheld tax, insurance premium deductions, and family names and My Numbers, for 4,571 staff and family members. No harm from the leaked data has been confirmed. [1]

Timeline

  1. Detected 2026-01-19
  2. Disclosed 2026-01-23
  3. 4 days

Attack or cause

Method
[Misdelivery]
Impact
[Data leak]
Entry point
E-mail

Data exposed or at risk

[Name][Date of birth][Postal address][My Number][Employment]

Organizations involved

Open in organization search

Sources

  1. [1][Official]職員の個人情報の漏えい事案の発生についてMinistry of Agriculture, Forestry and Fisheries · 2026-01-23
  2. [2][News]メール誤送信で農林水産省 職員及びその家族 4,571 人分のマイナンバー含む情報漏えいScanNetSecurity · 2026-02-12 08:05