> JapanHacked_
[Resolved][Severity: Critical][Intrusion]

Seino: intrusion into its web services

Unauthorized access to Mitsukaru Soko was detected on August 20. November's report identified potential exposure of about 1,800 warehouse-service member records and 20 My Seino credential records, without confirmed misuse. The warehouse service resumed on September 12 after remediation.

Disclosed

2025-08-21

Organizations involved

1

Leaked or at risk

1.8K

1,800

Downtime

Unknown

Timeline

  1. Detected 2025-08-20
  2. Disclosed 2025-08-21
  3. Resolved 2025-09-12
  4. 23 days

Attack or cause

Method
[Intrusion]
Impact
[Data leak][Service outage]
Entry point
Web app

Data exposed or at risk

[Name][Postal address][Phone number][E-mail address][Passwords]

Organizations involved

Open in organization search

Sources

  1. [1][Official]当社webサービス不正アクセスに伴う情報漏えいについてのお詫びとご報告Seino Transportation Co., Ltd. · 2025-11-05