CVE-2026-25739

Indico is an event management system that uses Flask-Multipass, a multi-backend authentication system for Flask. Versions prior to 3.3.10 are vulnerable to cross-site scripting when uploading certain file types as materials. Users should upgrade to version 3.3.10 to receive a patch. To apply the fix itself updating is sufficient, but to benefit from the strict Content Security Policy (CSP) Indico now applies by default for file downloads, update the webserver config in case one uses nginx with Indico's `STATIC_FILE_METHOD` set to `xaccelredirect`. For further directions, consult the GitHub Security advisory or Indico setup documentation. Some workarounds are available. Use the webserver config to apply a strict CSP for material download endpoints, and/or only let trustworthy users create content (including material uploads, which speakers can typically do as well) on Indico.

Affected products

Flask-Multipass, Indico

Cern Indico

< 3.3.10

Fix

Available

CVSS 3.1

5.4 MEDIUM

EPSS

0.2% (6th percentile)

Weakness

CWE-79

NVD status

Analyzed

Published

2026-02-19

No exploit for CVE-2026-25739 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.