What happened
Vikunja from 1.0.0-rc0 before 2.7.0 contains an improper authorization vulnerability in RecalculateTaskPositions that allows authenticated users with zero accessible projects to write task_positions rows for all tasks instance-wide. Attackers can delete their Inbox after repointing default_project_id, then create empty-filter saved filters to persist cross-tenant references and amplify writes for denial of service.
Affected versions
vikunja: 1.0.0-rc0 through before 2.7.0 (semver) Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.