6.1
/ 10
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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.
Basic Information
ID
CVE-2025-66469
Source
GitHub_M
Published
Dec 8, 2025 at 23:54
Affected Product
Vendor
zauberzeug
Product
nicegui
Version
< 3.4.0
Affected Versions
zauberzeug nicegui < 3.4.0