BPossible leakAugust 15, 2026 announced

株式会社両毛システムズData breach / unauthorized access incident

Reviewed by Yutaro SasaoWritten by Leak Watch editorial teamAugust 15, 2026 published ・ October 20, 2026 updated

Occurred on: August 12, 2026
Announced on: August 15, 2026
Severity: BIncidents centered on names and contact details.
Scale: Unknown
Main impact: Unauthorized use of VPN accounts allowed intrusion into the internal network, potentially exposing information of business partners, customers, and employees. The number and types of personal data are currently under review.
Information involved: User / member ID
Cause / key point: It has been announced that the intrusion occurred due to misuse of VPN accounts.
Industry: IT & telecom
Listing / capital: Listed company東証スタンダード 9691(両毛システムズ)
Sources: 両毛システムズ公式発表
Last updated: October 20, 2026

Stock price reaction to the disclosure両毛システムズ / 東証スタンダード 9691

2026.07.26 〜 2026.09.05Loading…

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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