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Incidents on Oct 30, 2026

Publication date: Dates are source publication dates (JST), not occurrence dates.

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Showing 31 of 31 incidents

Incidents on Oct 30, 2026
DateTargetSummaryClassificationSource links
LEAK-865DCM CorporationA 753,272 peopleUnauthorized access to Yumirlink's email distribution service "Cuenote FC" confirmed the leakage of personal information of 753,272 people. The leaked information includes email addresses, member IDs, names, genders, dates of birth, and prefectures of residence. Passwords and credit card information were not leaked.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-795Shuppin Co., Ltd.B 77,204 recordsShuppin Co., Ltd. announced that unauthorized access occurred at its contractor, Ymirlink Inc., potentially leading to the leakage of personal information. The information that may have been leaked includes 77,204 records of email addresses, point balances, point expiration dates, and prefecture names. It was stated that credit card information and login passwords were not leaked.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-981Value Commerce Co., Ltd.C 6,096 recordsValue Commerce Co., Ltd. announced that unauthorized access occurred in the email distribution service Cuenote FC it uses, potentially leading to the leakage of registered customer personal information. Currently, the number of email addresses that may have been leaked is reported as 6,096 records (a total of 7,588 records), but specific details of the information are under investigation.
Unauthorized access & data leakPossibleOfficial statement
LEAK-796DHC CorporationC 5,096 recordsOn October 28, 2026, unauthorized access by a third party was confirmed on DHC Corporation's online shop, resulting in the alteration of member information for 5,096 records, as well as unauthorized new member registrations and suspicious orders. Measures are currently being implemented to prevent further damage, and a report has been made to the Personal Information Protection Commission.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-784Ministry of Foreign AffairsC 3,600 recordsThe Ministry of Foreign Affairs announced that there was unauthorized access to a network capable of external communication, and approximately 3,600 records of personal information may have been leaked. Among these, about 900 records pertained to individuals other than ministry staff, and no highly confidential information was included. Unauthorized access was detected on July 27, and immediate blocking measures were taken. Currently, no secondary damage such as misuse of personal information has been confirmed.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-811Kumamoto CityC 1,084 peopleKumamoto City announced that 1,084 people's email addresses and usernames (some real names) were leaked from the system of Palan, the contractor for the "Kumamoto Castle and Central Shopping District AR Stamp Rally" conducted in 2024. No secondary damage has been confirmed.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-782Ryoubi SystemsD 778 recordsUnauthorized access occurred in the health check reservation system "AITEL," confirming the possibility of leakage of 778 records of personal information. The leaked information includes names, genders, dates of birth, phone numbers, email addresses, addresses, and reservation information. Currently, reports have been made to the police and relevant ministries, and investigations are ongoing.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-788Chuo CityE 14 recordsUnauthorized access occurred on the Chuo City Employment and Support Project portal site "Chuo City Job WEB," and it was announced that there is a possibility that personal information from 14 records submitted through the inquiry form has leaked externally.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-759Takaichi AdministrationReports have emerged regarding a data breach involving personal information related to the Takaichi Administration, with experts discussing defense measures. Specific details of the damage remain unclear, but there are mentions of the background of cyber attacks.
Unauthorized access & data leakUnverified reportNews report
LEAK-769ASCII.jpThe risks of information leakage related to generative AI were explained, particularly highlighting examples of information that should not be input into generative AI.
Unauthorized access & data leakUnverified reportNews report
LEAK-773Tokyo Electric Power Company Holdings, Inc.It was reported that the server of Japan Transportation Co., Ltd., a contractor, was accessed illegally, potentially leaking personal information of Tokyo Electric Power executives and employees. The potentially leaked information includes names, job titles, home addresses, and phone numbers. No secondary damage has been confirmed at this time.
Unauthorized access & data leakPossibleOfficial statement
LEAK-774GovernmentUnauthorized access resulted in the leakage of personal information for approximately 260,000,000 individuals from April to October 16, according to the government's Personal Information Protection Commission. The number of reported incidents reached 2,094, with a sharp increase in October.
Unauthorized access & data leakUnverified reportNews report
LEAK-775Matsuya Foods Holdings Co., Ltd.Unauthorized access occurred to the official Matsuya app, confirming the leakage of approximately 2,380,000 pieces of personal information. The leaked information includes member IDs, names, phone numbers, dates of birth, email addresses, encrypted passwords, and Matsuya points. An investigation into the cause is currently underway.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-776Ryohin KeikakuThe official MUJI app announced a potential leak of approximately 27,000,000 customer information records. The leaked information includes email addresses, birth dates, and gender, but does not include credit card information, names, addresses, or phone numbers. Currently, there is no confirmed misuse of the information, but there are warnings about the possibility of phishing emails.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-778Rivers EdgeBetween September and October 2026, major domestic companies reported a series of incidents involving unauthorized access and information leaks due to ransomware, leading to service disruptions. In particular, leaks from email distribution companies continued, with Ymirlink confirming a total of approximately 51,630,000 records leaked.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-783World Co., Ltd.Unauthorized access occurred to the business server of Tin Pan Alley, a consolidated subsidiary of World Co., Ltd., and it was announced that approximately 1,200,000 member records may have been leaked. The potentially leaked information includes names, addresses, phone numbers, dates of birth, genders, and email addresses, but there is no confirmation of leaked credit card information or facial data.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-787Tokyu FudosanUnauthorized access by a third party was confirmed on the company's managed website, and there is a possibility that personal information that was registered and stored has leaked externally. Currently, investigations are underway to determine the cause and the extent of the impact.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-792NTT Smile EnergyNTT Smile Energy confirmed traces of unauthorized access to its solar power remote monitoring service 'Eco Megane', indicating a possible attack on the database server. Customer information may have been leaked, including names, addresses, phone numbers, email addresses, login IDs, and passwords. A detailed investigation is currently underway.
Unauthorized access & data leakPossibleOfficial statement
LEAK-797KDDIKDDI announced that customer information of approximately 22,000 records may have been leaked. This was due to a vulnerability in the system of its partner, Lifenet Insurance. As of now, no exploitation has been confirmed.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-806All Nippon AirwaysAll Nippon Airways announced that a contractor for its passenger system experienced unauthorized access, potentially exposing some personal information of approximately 37,800 individuals to external viewing.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-810Okinawa PrefecturePersonal information was leaked due to unauthorized access to an external email distribution service provider used by the designated management facility "Okinawa Prefectural Forest" for its campsite reservation service. The leaked information included email addresses, nicknames, prefectures of residence, and member IDs.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-812INVOX CorporationSince September 2026, there have been a series of personal information leaks due to unauthorized access in Japan, prompting alerts from JPCERT/CC and IPA. APIs and BI tools have been particularly targeted.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-814IPA Independent Administrative Institution Information-Technology Promotion AgencyIPA announced that a data breach occurred due to unauthorized access. No details were provided regarding the specific damage or the types of data affected.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-815GMO Internet Group Inc.Unauthorized access to AI-related systems at GMO Internet Group Inc. was reported. Specific details regarding the extent of the damage or impact have not been disclosed.
Unauthorized access & data leakPossibleOfficial statement
LEAK-849Ishigaki CityIshigaki City issued a warning regarding unauthorized access related to the hometown tax portal site "Sato Furusato." Investigations confirmed that Ishigaki City was not subject to information leakage; however, unauthorized access occurred in related email distribution services, potentially leading to information leakage. Donors are advised to be cautious of suspicious emails or SMS messages.
Unauthorized access & data leakConfirmedOfficial statement
LEAK-855JPCERT/CCJPCERT/CC issued a warning regarding a series of unauthorized access incidents occurring in domestic organizations. The specific details of the damage and the extent of the impact remain unclear.
Unauthorized access & data leakPossibleOfficial statement
LEAK-860Okayama Prefectural PoliceOkayama Prefectural Police held a seminar to raise awareness about the ongoing cyber attacks and personal information leaks occurring nationwide.
Unauthorized access & data leakUnverified reportNews report
LEAK-867Fuji-Q HighlandThere are reports of possible unauthorized access to the reservation system management company for Fuji-Q Highland, resulting in the leakage of personal information for approximately 70,000 individuals.
Unauthorized access & data leakUnverified reportNews report
LEAK-872Vook Inc.Vook Inc. announced that a vulnerability in a data analysis tool used for internal operations was exploited, potentially leaking personal information of Vook members and individuals who made inquiries. The information that may have been leaked includes names, email addresses, phone numbers, addresses, and dates of birth, but does not include credit card or bank account information. A detailed investigation is currently underway.
Unauthorized access & data leakPossibleOfficial statement
LEAK-873Hiroshima Prefectural PoliceHiroshima Prefectural Police announced the possibility of a data breach involving personal information due to a cyber attack. There are concerns that the leaked information could be misused, leading to further harm. Specific cases of damage and preventive measures were also mentioned.
Unauthorized access & data leakPossibleOfficial statement
LEAK-919Shibushi CityThere was a report that Paydon may have leaked user personal information due to unauthorized access by a third party. The potentially leaked information includes Paydon users' email addresses, merchant email addresses, and payment information. The investigation into whether citizens' information has been leaked is ongoing.
Unauthorized access & data leakPossibleOfficial statement

Showing 20 of 31 cases

Incidents on Oct 30, 2026