CVE-2026-55064 Vikunja incomplete fix for CVE-2026-35595: Write-only user can detach shared project from parent hierarchy via parent_project_id=0

Vikunja is an open-source self-hosted task management platform. From 2.3.0 until 2.4.0, a user with Write but not Admin permission on a shared child project can detach it from its parent hierarchy by submitting parentprojectid equal to 0 to POST /api/v1/projects/project. The Project.CanUpdate...