> JapanHacked_
[Contained][Severity: Moderate][Misconfiguration]

OSIRO: up to 12,661 member IDs and display names on the community platform were viewed from outside

Member IDs, display names and icon image URLs on OSIRO were viewable from outside and were accessed. Up to 12,661 members are affected; 1,101 display names may be real names.

Disclosed

2026-11-04

Organizations involved

1

Leaked or at risk

12.7K

12,661

Downtime

Unknown

What happened

On 19 October a security check by OSIRO Inc. found that some member data on OSIRO could be viewed without logging in, and it fixed the system. On 28 October it matched access logs and confirmed that outsiders had actually accessed the data. The cause lies in its own system, not in community operators’ settings. It has reported to the privacy regulator. [1]

Up to 12,661 members registered or active between 17 December 2021 and 3 October 2026 are affected; their member IDs, display names and icon image URLs were viewed. 1,101 display names may be real names. The company says names, addresses, emails, phones, birth dates, passwords and card numbers were not accessed. [1]

Timeline

  1. Detected 2026-10-19
  2. Disclosed 2026-11-04
  3. 16 days

Attack or cause

Method
[Misconfiguration]
Impact
[Data leak]
Entry point
Web app

Data exposed or at risk

[Member or customer ID][Name]

Services hit

Organizations involved

Sources

  1. [1][Official]不正アクセスによる一部会員のID、表示名、アイコン画像URLの漏洩に関するご報告とお詫びOSIRO · 2026-11-04