Mr Max: unauthorized access to its app and online store
On the evening of 3 October, discount store chain Mr Max found suspicious access to the servers of its MrMax app and online store, stopped the services and blocked outside access. A third party had abused a function of the software the services run on to get into the server, and member IDs, names, emails and phone numbers of up to 1,735,154 people leaked. Addresses, birth dates, card data, passwords and purchase history did not leak.
Disclosed
2026-10-06
Organizations involved
1
Leaked or at risk
1.7M
1,735,154
Downtime
Unknown
Timeline
- Detected 2026-10-03
- Disclosed 2026-10-06
- 3 days
Attack or cause
- Method
- [Web app exploit]
- Impact
- [Data leak][Service outage]
- Entry point
- Web app
Data exposed or at risk
Organizations involved
[Breached][Critical]Fukuoka, Fukuoka, HigashiWholesale and retail trade1,735,154 leaked
Mr Max Ltd.
Sources
- [1][Official]不正アクセスによる情報流出に関するお詫びとお知らせMr Max · 2026-10-06
- [2][News]ミスターマックス、不正アクセスで最大173万人の会員情報流出Reuters · 2026-10-06