CVE-2026-56765

Summary (CVE-2026-56765): Vikunja prior to 2.2.1 contains two related authorization flaws. First, the LinkSharing.ReadAll endpoint exposes share hashes to users with read access, enabling permission escalation to admin-level shares. Second, the GetTaskAttachment endpoint performs permission check...

Vikunja: Unauthenticated Instance-Wide Data Breach via Link Share Hash Disclosure Chained with Cross-Project Attachment IDOR

Summary Two independently-exploitable authorization flaws in Vikunja can be chained to allow an unauthenticated attacker to download and delete every file attachment across all projects in a Vikunja instance. The ReadAll endpoint for link shares exposes share hashes including admin-level shares t...