PYSEC-2026-2184: Indico discloses local files resulting in Remote Code Execution through LaTeX injection

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. In versions prior to 3.3.12, due to vulnerabilities in TeXLive and obscure LaTeX syntax that allowed circumventing Indico's LaTeX sanitizer, it is possible to use specially-crafted LaTeX snippets which can read local files or execute code with the privileges of the user running Indico on the server. Note that if server-side LaTeX rendering is not in use (ie XELATEXPATH was not set in indico.conf), this vulnerability does not apply. It is recommended to update to Indico 3.3.12 as soon as possible. It is also strongly recommended to enable the containerized LaTeX renderer (using podman), which isolates it from the rest of the system. As a workaround, remove the XELATEXPATH setting from indico.conf (or comment it out or set it to None) and restart the indico-uwsgi and indico-celery services to disable LaTeX functionality.