Vikunja Vulnerable to Link Share Hash Disclosure via ReadAll Endpoint Enables Permission Escalation

Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.2, the LinkSharing.ReadAll() method allows link share authenticated users to list all link shares for a project, including their secret hashes. While LinkSharing.CanRead() correctly blocks link share users from reading individual shares via ReadOne, the ReadAllWeb handler bypasses this check by never calling CanRead(). An attacker with a read-only link share can retrieve hashes for write or admin link shares on the same project and authenticate with them, escalating to full admin access. Version 2.2.2 patches the issue.