BPossible leakSeptember 27, 2026 announced

スターツ出版（OZmall）Data breach / unauthorized access incident

Reviewed by Yutaro SasaoWritten by Leak Watch editorial teamSeptember 27, 2026 published ・ October 20, 2026 updated

Occurred on: Unconfirmed
Announced on: September 27, 2026
Severity: BIncidents centered on names and contact details.
Scale: 442,779 people
Main impact: Up to 442,779 email addresses may have been exposed, with some records including names and prefectures. A confirmed data leak has not been reported.
Information involved: Email addressFull name
Cause / key point: The cause is under investigation.
Industry: Media & entertainment
Listing / capital: Listed company東証スタンダード 7849(スターツ出版)
Sources: 当社への不正アクセスによる個人情報流出の可能性に関するお知らせ（第２報）
Last updated: October 20, 2026

Stock price reaction to the disclosureスターツ出版 / 東証スタンダード 7849

2026.09.07 〜 2026.10.18Loading…

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Written & reviewed

Reviewed byYutaro SasaoFounder & CEO, MediaLeap Inc.

CEO of MediaLeap Inc. Working on both sides of web advertising and web media since 2013; founded the company in May 2025.

Review scope: cross-checking against primary sources (official and government announcements), verifying claims stay within the facts, and checking source attribution。Last reviewed: October 20, 2026

Written by:Leak Watch editorial team (AI-assisted drafts verified against sources by the editorial team) · Reviewer profile · Request a correction