GHSA-hq66-9qg8-jwqg: Vikunja 0.18.0 before 2.7.1 Privilege Escalation via Account Deletion

Vikunja from 0.18.0 before 2.7.1 contains a privilege escalation vulnerability that allows team owners to gain admin or ownership of read-only shared projects by deleting accounts. Attackers can create a bot, add it to their team, and delete it through the bots endpoint, triggering ensureProjectAdminUser to promote read-only shares and lock out the real owner.