Vulnerability Description
NiceGUI is a Python-based UI framework. Versions 3.3.1 and below are vulnerable to Reflected XSS through its ui.add_css, ui.add_scss, and ui.add_sass functions. The functions lack proper sanitization or encoding for the JavaScript context they generate. An attacker can break out of the intended <style> or <script> tags by injecting closing tags (e.g., </style> or </script>), allowing for the execution of arbitrary JavaScript. This issue is fixed in version 3.4.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Zauberzeug | Nicegui | < 3.4.0 |
Related Weaknesses (CWE)
References
- https://github.com/zauberzeug/nicegui/commit/a8fd25b7d5e23afb1952d0f60a1940e18b5Patch
- https://github.com/zauberzeug/nicegui/security/advisories/GHSA-72qc-wxch-74mgExploitVendor Advisory
- https://github.com/zauberzeug/nicegui/security/advisories/GHSA-72qc-wxch-74mgExploitVendor Advisory
FAQ
What is CVE-2025-66469?
CVE-2025-66469 is a vulnerability with a CVSS score of 6.1 (MEDIUM). NiceGUI is a Python-based UI framework. Versions 3.3.1 and below are vulnerable to Reflected XSS through its ui.add_css, ui.add_scss, and ui.add_sass functions. The functions lack proper sanitization ...
How severe is CVE-2025-66469?
CVE-2025-66469 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-66469?
Check the references section above for vendor advisories and patch information. Affected products include: Zauberzeug Nicegui.