CVE-2026-55064: Go-Vikunja Vikunja

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

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 parent_project_id equal to 0 to POST /api/v1/projects/{project}. The Project.CanUpdate authorization check in pkg/models/project_permissions.go and UpdateProject logic in pkg/models/project.go only gate nonzero parent values, while UpdateProject always persists parent_project_id, so the explicit zero value bypasses the Admin requirement introduced for CVE-2026-35595. Detachment severs the recursive permission-inheritance chain and can disrupt the owner’s hierarchy and inherited collaborator access. This issue is fixed in version 2.4.0.

Affected products

• Go-Vikunja Vikunja: from 2.3.0, before 2.4.0 (fixed in 2.4.0)

Published 2026-08-28. Last modified 2026-09-09.