CVE-2026-25739 Indico affected by Cross-Site-Scripting via material uploads
Attackers can execute arbitrary scripts via malicious file uploads in Indico, potentially compromising user accounts and session data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-25739?
CVE-2026-25739 is a medium-severity cross-site scripting vulnerability in indico, published on 19 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-25739?
3 open source packages ship an affected version, including indico. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
indico PyPI | All versions | 3.3.10 |
indico PyPI | All versions | 3.3.10 |
indico PyPI | All versions | 3.3.10 |
Products include Cern Indico.
How do I fix CVE-2026-25739?
Upgrade indico to 3.3.10 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-25739 being exploited?
There is no known exploitation of CVE-2026-25739 in the wild and no public exploit code.
Other vulnerabilities in indico
- CVE-2026-33046 Indico discloses local files resulting in Remote Code Execution through LaTeX injection
- CVE-2021-30185 Indico Tampering with links (e.g. password reset) in sent emails
- CVE-2026-25738 Indico has Server-Side Request Forgery (SSRF) in multiple places
- CVE-2026-28352 Indico missing access check in event series management API
- CVE-2023-37901 Cross-Site-Scripting via confirmation prompts
Sources
Also known as GHSA-jxc4-54g3-j7vp, PYSEC-2026-2182.