コタData breach / unauthorized access incident
- Occurred on
- Unconfirmed
- Announced on
- August 20, 2026
- Severity
- AFinancial and HR records — information that easily translates into monetary damage.
- Scale
- 55,000 records
- Main impact
- In addition to customer and personnel information, there is a risk that about 55,000 records of shareholder information and share holdings were exposed. A confirmed data leak has not been announced.
- Information involved
- Not specified in the disclosure
- Cause / key point
- The cause is under investigation.
- Industry
- Manufacturing
- Listing / capital
- Listed company東証プライム 4923(コタ)
- Last updated
- October 20, 2026
Stock price reaction to the disclosureコタ / 東証プライム 4923
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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: Under investigation / not stated(Cause not disclosed)
Read the Under investigation / not stated guide and national trends →