メドレー（アットリンク）Data breach / unauthorized access incident
- Occurred on
- Unconfirmed
- Announced on
- October 15, 2026
- Severity
- SCompromise of deep personal data or usable credentials.
- Scale
- 787 records
- Main impact
- It was announced that unauthorized access to the medical institution support system "アットリンク" may have led to leakage of patients' personal information. The maximum number of affected medical institutions is 787, and the data items and number of individuals are under investigation.
- Information involved
- Health & medical data
- Cause / key point
- Cause is under investigation.
- Industry
- Healthcare
- Listing / capital
- Listed company東証プライム 4480(メドレー)
- Last updated
- October 20, 2026
Stock price reaction to the disclosureメドレー / 東証プライム 4480
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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: Unauthorized access (method undisclosed)(Breached, but the technique was not identified or disclosed)
Read the Unauthorized access (method undisclosed) guide and national trends →