CVE-2026-25739
Cross-Site Scripting in Indico Materials Upload Pre
Publication date: 2026-02-19
Last updated on: 2026-02-26
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| cern | indico | to 3.3.10 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects Indico, an event management system that uses Flask-Multipass for authentication. Versions prior to 3.3.10 are vulnerable to cross-site scripting (XSS) attacks when uploading certain file types as materials.
Cross-site scripting allows attackers to inject malicious scripts into web pages viewed by other users, potentially compromising their security.
The vulnerability can be mitigated by upgrading Indico to version 3.3.10, which includes a patch. Additional security can be achieved by applying a strict Content Security Policy (CSP) for file downloads, especially when using nginx with Indico's STATIC_FILE_METHOD set to xaccelredirect.
How can this vulnerability impact me? :
This cross-site scripting vulnerability can allow attackers to execute malicious scripts in the context of users who view the uploaded materials, potentially leading to theft of sensitive information, session hijacking, or other malicious actions.
Users who can upload materials, such as speakers or trusted content creators, could inadvertently or maliciously upload files that exploit this vulnerability.
Without applying the patch or additional security measures like a strict Content Security Policy, the system and its users remain at risk.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade Indico to version 3.3.10 or later, which includes the patch for the cross-site scripting issue.
Additionally, if you use nginx with Indico's STATIC_FILE_METHOD set to xaccelredirect, update your webserver configuration to apply a strict Content Security Policy (CSP) for file download endpoints.
As a workaround, you can restrict material uploads to only trustworthy users, such as speakers, to reduce the risk of malicious file uploads.
For further directions, consult the GitHub Security advisory or Indico setup documentation.