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

Temairazu: unauthorized access to the TEMAIRAZU hotel booking management service

From late on 21 September, guests of hotels using the TEMAIRAZU series, which manages listings across several booking sites, received suspicious WhatsApp messages, emails and texts that appeared to know their bookings. Temairazu confirmed unauthorized access to its system; it cannot rule out that some guest data was viewed or taken. The messages asked guests to confirm bookings, re-enter card details or make urgent payments on fake sites. It identified and fixed the cause and restarted the functions it had paused. Its October 9 disclosure identified up to about 4.45 million people whose names, contacts, hotels, stay dates and room charges may have been viewed or acquired. Some functions stopped from 10:58 to 21:48 on September 24 and then resumed; the core reservation/inventory/rate integration engine did not stop.

Disclosed

2026-09-28

Organizations involved

1

Leaked or at risk

4.5M

4,450,000

Downtime

Unknown

Timeline

  1. Started, Detected 2026-09-21
  2. Disclosed 2026-09-28
  3. 7 days

Attack or cause

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

Data exposed or at risk

[Name][Phone number][E-mail address][Purchase history]

Services hit

Organizations involved

Open in organization search

Sources

  1. [1][News]宿泊予約管理サービス「TEMAIRAZU」に不正アクセス、予約者に不審なメッセージがあり判明INTERNET Watch · 2026-10-01
  2. [2][News]手間いらず、システムに不正アクセス 複数宿泊施設の予約客に不審メッセージTRAICY · 2026-09-29
  3. [3][Official]当社システムへの不正アクセスに関する調査状況および対応についてTemairazu · 2026-10-09