CVE-2026-107396Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Prior to 3.3.13, users who can manage events or create content, including speakers who can upload material, can store crafted javascript URLs in fields that accept custom URLs. A user who follows one of these URLs can execute attacker-controlled script in the user's browser in the Indico origin. This issue is fixed in version 3.3.13.