2026-10-23
Comic Cmoa Member Data Breach (Up to About 4.2 Million Records in Log Files): Email Addresses and Dates of Birth Leaked — What Users Should Do
NTT Solmare Corporation, which runs the Japanese e-book store Comic Cmoa (コミックシーモア), published four notices about unauthorized access to the service, from a first notice on October 15, 2026 to a fourth report on October 21. According to the company, on October 15 it judged that unauthorized access from outside to its servers had very likely taken place and suspended the service at 11:35. In its second report on October 16 it said it had confirmed that member data in the system that manages member information had leaked to a third party (the count was still being examined). In its third report on October 18 it said it had identified the intrusion route and attack method and was dealing with them, and that some system log files had also been viewed and taken. In its fourth report on October 21 it described the data confirmed as leaked as 319 records of registration data in the member database (email address, hashed password, nickname, date of birth, gender) and up to about 4.2 million records in system log files (email address, nickname, date of birth, gender; no passwords; possibly including duplicates for the same person). It says credit card data is not held in the affected systems and did not leak, and that no leak of purchase histories and no leak, loss or damage of MY Bookshelf (users' libraries) has been confirmed. It says identifying and blocking the intrusion route and attack method is complete, but has not disclosed what they were. Affected people will be contacted by email. The service remains suspended and is to resume in stages, starting with web reading of purchased titles; all users will be asked to reset their passwords on resumption. This site's take: anyone who uses the same email address and password as on Comic Cmoa for another service should change that password today, should not open links in emails claiming to be the company, and should check through NTT Solmare's news release page opened themselves.