i-plug（OfferBox）Data breach / unauthorized access incident
- Occurred on
- May 12, 2026
- Announced on
- October 5, 2026
- Severity
- AFinancial and HR records — information that easily translates into monetary damage.
- Scale
- 314,000 people
- Main impact
- Names and email addresses of up to 31.4万人 individuals were accessible to companies using OfferBox.
- Information involved
- Email addressFull name
- Cause / key point
- Access controls were inadequate due to incorrect system configuration.
- Industry
- IT & telecom
- Listing / capital
- Listed company東証グロース 4177(i‐plug)
- Last updated
- October 20, 2026
Stock price reaction to the disclosurei‐plug / 東証グロース 4177
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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:
Written by:Leak Watch editorial team (AI-assisted drafts verified against sources by the editorial team) · Reviewer profile · Request a correction
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Attack method classification: Misconfiguration & access-control gaps(Data left readable by anyone)
Read the Misconfiguration & access-control gaps guide and national trends →