Kobunshoin

Japan-based services

Aliases / services: 光文書院 / 株式会社光文書院 / KOBUNSHOIN PUBLISHING CO., LTD. / ひまわり先生 / ドリルプラネット / CBTタワー / Kobunshoin
Official website: https://www.kobun.co.jp/

Each response applies only to its stated service scope. “Not listed” does not mean unpatched or unaffected.

Response status by service

Listed services and systems

Response status: Maintenance ended; all services restored
Response information checked: 2026-10-27 Rechecked: 2026-10-27

Kobunshoin publishes school materials and provides digital learning services.

Some services entered PHP-related maintenance at 18:00 on 22 October. After required measures and checks, maintenance ended at 05:00 on 23 October and all services resumed normal operation.

What users should do

Use the services normally; contact Himawari support if a problem remains.

Official service URL

https://www.kobun.co.jp/

Source URLs

PHP2Shell response and scopehttps://www.kobun.co.jp/2026/10/23/notice-20261023/Response evidence
Operating entityhttps://www.kobun.co.jp/corp/profile/Service and operation documentation

Related official sources

PHP2Shell response and scopeOfficial notice
Operating entityOfficial information directory