日本電気株式会社Data breach / unauthorized access incident
- Occurred on
- September 21, 2026
- Announced on
- October 20, 2026
- Severity
- SCompromise of deep personal data or usable credentials.
- Scale
- Unknown
- Main impact
- Unauthorized access from a contractor's device using legitimate accounts encrypted files on the servers, rendering various systems unusable. Also, files in a cloud storage used among stakeholders were leaked, and it was confirmed they contained customers' personal information and system-related information.
- Information involved
- Not specified in the disclosure
- Cause / key point
- Unauthorized access due to a contractor receiving a cyberattack in late September, with stolen legitimate account credentials being abused.About Abuse of credentials
- Industry
- IT & telecom
- Listing / capital
- Listed company東証プライム 6701
- Sources
- Last updated
- October 22, 2026
Stock price reaction to the disclosure日本電気株式会社 / 東証プライム 6701
Stock information is reference data based on Yahoo Finance and may be delayed. This site does not solicit or advise investment and does not guarantee the accuracy or completeness of this information. We accept no liability for any investment decision based on it.
Is this incident worth paying attention to?
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
Related incidents
Browse the database →Incidents sharing the same company, service, attack method or industry (grouped automatically from the disclosures).
Incidents related to "クラウドストレージ"
Incidents where the damage spread through the same service or system.
Same attack method
- A日本経済新聞社(日経)2026.10.16 announced・Affected 1,830,000 records
- Sチャーム本店2026.09.01 announced・Affected 370,000 records
- ACAMPFIRE2026.06.02 announced・Affected 225,846 accounts
- Aウエーブ（Webアップロード）2026.04.01 announced・Affected 176,810 records
- Aシチズン時計（問い合わせ管理）2026.10.06 announced・Affected 100,000 people
- Bイノベーション（GitHub）2026.08.07 announced・Affected 62,689 people
Same industry
- SSEストアー(ショップサーブ)2026.10.16 announced・Affected 23,356,000 people
- SSソースネクスト2026.10.15 announced・Affected 22,519,960 records
- SSコミューン（Commune・Commune for Work）2026.10.09 announced・Affected 307,000 people
- SSIDCフロンティア（IDCFクラウド）2026.10.07 announced・Affected 48 records
- SS楽天ドライブ2026.10.06 announced・Affected 15,382 accounts
- SSHelpfeel（Gyazo）2026.09.16 announced・Affected 23,620,000 records
Attack method classification: Abuse of credentials(Logging in legitimately with leaked or guessed passwords)
Read the Abuse of credentials guide and national trends →