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574 results
Disclosed 2026-08-21Updated 2026-10-27 20:08Tokyo[Contained][Severity: Major]
Rakuten Books Network: intruders reach work PCs holding 33,333 Rakuten Books delivery addresses[Intrusion][Data leak]Leaked 33.3KOrganizations 2Disclosed 2026-08-20Updated 2026-10-22Osaka[Contained][Severity: Major]
Expo 2025 Osaka, Kansai, Japan: unauthorized access to a subcontractor's Microsoft 365 account[Phishing][Credential abuse][Data leak]Organizations 1Disclosed 2026-08-18Updated 2026-10-22Tokyo[Contained][Severity: Critical]
VOISING: unauthorized access to a BI tool it uses[Web app exploit][Data leak]Leaked 170KOrganizations 1Disclosed 2026-08-17Updated 2026-10-23Osaka[Contained][Severity: Critical]
SAKURA internet: unauthorized access to rental servers and the sales system[Intrusion][Malware][Data leak]Leaked 1.4MOrganizations 1Disclosed 2026-08-15Updated 2026-10-23Gunma, Mie, Nagano, Saitama[Investigating][Severity: Critical]
Ryomo Systems: ransomware attack[Ransomware][Credential abuse][Data leak]Organizations 5Disclosed 2026-08-14Updated 2026-10-22Kanagawa, Tokyo[Contained][Severity: Major]
T museum: Unko Museum website tampered with[Web app exploit][Data leak][Site defacement]Leaked 4Organizations 2Disclosed 2026-08-13Updated 2026-10-23Gunma[Contained][Severity: Critical]
Charm: unauthorized access to its pet supplies online store[Intrusion][Data leak][Service outage]Leaked 430KOrganizations 1Disclosed 2026-08-13Updated 2026-10-22Tokyo[Investigating][Severity: Moderate]
Tokyo Gas Network: work laptop lost[Lost device][Data leak]Leaked 20KOrganizations 1Disclosed 2026-08-12Updated 2026-10-22Tokyo[Contained][Severity: Critical]
White Essence: unauthorized access to its booking site and core system[Web app exploit][Data leak][Service outage]Leaked 1.1MOrganizations 1Disclosed 2026-08-10Updated 2026-10-23Tokyo[Resolved][Severity: Critical]
REXT: ransomware attack on the headquarters and store network[Ransomware][Data leak][Service outage]Leaked 1MOrganizations 2Disclosed 2026-08-10Updated 2026-10-22Tokyo[Investigating][Severity: Critical]
RIZAP: unauthorized access to the APORITO online store[Web app exploit][Data leak][Service outage]Organizations 1Disclosed 2026-08-07Updated 2026-10-23Saitama[Investigating][Severity: Major]
JST: unauthorized access to staff mailboxes[Intrusion][Data leak]Leaked 18KOrganizations 1Disclosed 2026-08-06Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Ambition DX Holdings: ransomware attack[Ransomware][Intrusion][Data leak]Leaked 580KOrganizations 1Disclosed 2026-08-06Updated 2026-10-23Kanagawa[Resolved][Severity: Moderate]
CEC: ransomware attack on its Tokyo No. 2 datacenter[Ransomware][Service outage]Organizations 1Disclosed 2026-08-05Updated 2026-10-22Tokyo[Investigating][Severity: Major]
Kyodo News: staff accounts misused[Credential abuse][Data leak]Leaked 6KOrganizations 1Disclosed 2026-08-04Updated 2026-10-23Aichi[Contained][Severity: Major]
Chubu Electric Power: unauthorized access to email and contacts[Credential abuse][Data leak]Leaked 71.7KOrganizations 1Disclosed 2026-08-04Updated 2026-10-22Tokyo[Contained][Severity: Major]
Innovation: unauthorized access to its GitHub[Credential abuse][Data leak]Leaked 62.7KOrganizations 1Disclosed 2026-08-03Updated 2026-10-22Tokyo[Contained][Severity: Major]
Kodansha: unauthorized access to a company email account[Phishing][Credential abuse][Data leak]Leaked 3.8KOrganizations 1Disclosed 2026-08-01Updated 2026-10-22Ishikawa, Tokyo[Contained][Severity: Critical]
Estore: shopper data leaked from ShopServe[Web app exploit][Data leak]Leaked 23.4MOrganizations 2Disclosed 2026-07-31Updated 2026-10-23Tokyo[Contained][Severity: Critical]
EPARK Relax & Esthe: unauthorized access to the PeakManager booking system[Credential abuse][Data leak]Leaked 33MOrganizations 1Disclosed 2026-07-29Updated 2026-10-23Tokyo[Contained][Severity: Major]
Life Insurance Association: user data viewable in the policy inquiry system[Misconfiguration][Data leak][Service outage]Leaked 37.9KOrganizations 1Disclosed 2026-07-26Updated 2026-10-23Osaka[Contained][Severity: Critical]
NTT SmartConnect: unauthorized access to Smile Server[Intrusion][Service outage]Organizations 1Disclosed 2026-07-24Updated 2026-10-22Tokyo[Contained][Severity: Critical]
murauchi.com: unauthorized access[Web app exploit][Data leak][Service outage]Leaked 7.7MOrganizations 1Disclosed 2026-07-16Updated 2026-10-23Tokyo[Resolved][Severity: Moderate]
Nissan Chemical: unauthorized logins to its cloud environment[Credential abuse]Organizations 1Disclosed 2026-07-14Updated 2026-10-23Tokyo[Contained][Severity: Major]
Media4u: unauthorized access to its SMS delivery system[Web app exploit][Data leak]Leaked 95.4KOrganizations 1Disclosed 2026-07-13Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Nichirei: cyberattack[Intrusion][Data leak][Service outage]Leaked 43.7KOrganizations 1Disclosed 2026-07-13Updated 2026-10-22Tokyo[Investigating][Severity: Critical]
Nihon Kotsu: malware attack[Malware][Data leak][Service outage]Organizations 1Disclosed 2026-07-02Updated 2026-10-23Aichi[Investigating][Severity: Critical]
Meitetsu Kyosho: ransomware attack[Ransomware][Data leak][Service outage]Organizations 2Disclosed 2026-07-01Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Kaga Solution Network: unauthorized access to the Academico Navi student PC store[Web app exploit][Data leak][Service outage]Leaked 170KOrganizations 3Disclosed 2026-06-30Updated 2026-10-23Tokyo[Investigating][Severity: Major]
Musashino University: ransomware; files in shared folders were taken[Ransomware][Service outage][Data leak]Organizations 1Disclosed 2026-06-30Updated 2026-10-22Tokyo[Contained][Severity: Critical]
Aflac Life Insurance Japan: unauthorized access to online systems[Web app exploit][Data leak][Service outage]Leaked 4.4MOrganizations 1Disclosed 2026-06-23Updated 2026-10-22Aichi, Kagawa, Tokyo[Contained][Severity: Critical]
KDDI: unauthorized access to its mail system for ISPs[Intrusion][Data leak]Leaked 12.2MOrganizations 7Disclosed 2026-06-22Updated 2026-10-23Osaka[Ongoing][Severity: Critical]
Faith Group: ransomware attack[Ransomware][Intrusion][Data leak][Service outage]Organizations 1Disclosed 2026-06-22Updated 2026-10-23Tokyo[Investigating][Severity: Critical]
Hands Holdings: ransomware attack[Ransomware][Data leak][Service outage]Organizations 1Disclosed 2026-06-19Updated 2026-10-23Osaka, Tokyo[Contained][Severity: Critical]
Delightful: unauthorized access to the Meruhaikun email delivery system[Web app exploit][Intrusion][Data leak][Service outage]Leaked 1.7MOrganizations 4Disclosed 2026-06-19Updated 2026-10-22Osaka[Investigating][Severity: Major]
Gendai Butsudan: unauthorized access to its service network[Intrusion][Data leak]Organizations 1Disclosed 2026-06-16Updated 2026-10-22Tokyo[Resolved][Severity: Critical]
Komatsu: misconfigured external user directory[Misconfiguration][Data leak]Leaked 139.3KOrganizations 1Disclosed 2026-06-16Updated 2026-10-22Hiroshima[Contained][Severity: Moderate]
Mikasa: data may have leaked from a disposed PC[Lost device][Data leak]Leaked 4.3KOrganizations 1Disclosed 2026-06-15Updated 2026-10-23Tokyo[Investigating][Severity: Moderate]
Factory Japan Group: unauthorized access to its servers[Intrusion]Organizations 1Disclosed 2026-06-15Updated 2026-10-23Saga[Contained][Severity: Critical]
Saga Hirakawaya: card data leaked from its online shop[Web app exploit][Data leak][Service outage]Leaked 73.2KOrganizations 1Disclosed 2026-06-15Updated 2026-10-22Miyagi[Contained][Severity: Critical]
Act-Sen: ransomware attack on its work management system[Ransomware][Data leak][Service outage]Organizations 1Disclosed 2026-06-12Updated 2026-10-22Tokyo[Contained][Severity: Major]
D&M: ransomware attack[Ransomware][Data leak]Leaked 633Organizations 1Disclosed 2026-06-10Updated 2026-10-22Tokyo[Contained][Severity: Critical]
Kaizen Tech Agent: suspected data theft by a former employee[Insider][Data leak]Leaked 9.7KOrganizations 1Disclosed 2026-06-08Updated 2026-10-23Fukuoka[Investigating][Severity: Critical]
Kyushu Electric Power Transmission and Distribution: backup media missing[Lost device][Data leak]Leaked 13.5MOrganizations 1Disclosed 2026-06-05Updated 2026-10-22Tokyo[Contained][Severity: Major]
en: credential stuffing attack on the Middle no Tenshoku job site[Credential abuse][Data leak]Leaked 2.5KOrganizations 1Disclosed 2026-06-05Updated 2026-10-22Tokyo[Contained][Severity: Critical]
Sen: unauthorized access to Hai Cheese! Photo[Web app exploit][Data leak][Service outage]Organizations 1Disclosed 2026-06-04Updated 2026-10-23Osaka[Contained][Severity: Critical]
Visual Arts: unauthorized access to its cloud storage[Credential abuse][Data leak][Service outage]Leaked 6KOrganizations 1Disclosed 2026-06-04Updated 2026-10-22Hokkaido[Investigating][Severity: Moderate]
Shokusou: ransomware attack[Ransomware][Service outage]Organizations 1Disclosed 2026-05-28Updated 2026-10-22Tokyo[Contained][Severity: Major]
Asoview: unauthorized access to the satsuki booking system[Intrusion][Data leak]Leaked 27.2KOrganizations 1Disclosed 2026-05-28Updated 2026-10-22Tokyo[Investigating][Severity: Critical]
Polaris Holdings: unauthorized access to its Booking.com account[Credential abuse][Fraud][Financial loss]Organizations 1