Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the is_user_channel_member function checks whether a ChannelMember row exists but does not check the is_active field. When a user is deactivated from a group or DM channel (removed by the channel owner, or leaves voluntarily), their membership row persists with is_active=False and status='left'. Because the authorization check ignores this field, the deactivated user retains full read and write access to the channel via direct API calls. This vulnerability is fixed in 0.9.0.

Open WebUI: Deactivated Channel Members Retain Full Access to Group/DM Channels

Уязвимость функции is_user_channel_member() веб-интерфейса на базе искусственного интеллекта Open WebUI, позволяющая нарушителю обойти существующие механизмы безопасности и получить доступ на чтение и изменение данных