CVE-2026-35594 Vikunja Link Share JWT tokens remain valid for 72 hours after share deletion or permission downgrade

Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's link share authentication GetLinkShareFromClaims in pkg/models/linksharing.go constructs authorization objects entirely from JWT claims without any server-side database validation. When a project owner delet...