lunary-ai/lunary is vulnerable to an authentication issue due to improper validation of email addresses during the signup process. Specifically, the server fails to treat email addresses as case insensitive, allowing the creation of multiple accounts with the same email address by varying the case of the email characters. For example, accounts for 'abc@gmail.com' and 'Abc@gmail.com' can both be created, leading to potential impersonation and confusion among users.

By knowing an organization's ID, an attacker can join the organization without permission and gain the ability to read and modify all data within that organization. This vulnerability allows unauthorized access and modification of sensitive information, posing a significant security risk. The flaw is due to insufficient verification of user permissions when joining an organization.