CVE-2025-66469

Published: Dec 9, 2025Modified: Jun 17, 2026

6.1

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Exploitability: 2.8 / Impact: 2.7

Source: security-advisories@github.com (Secondary)

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.

Affected (1)

Products: Zauberzeug: Nicegui

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Zauberzeug Nicegui	Before 3.4.0

Related CWEs

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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.

References (3)

https://github.com/zauberzeug/nicegui/commit/a8fd25b7d5e23afb1952d0f60a1940e18b5f1ca8

Source: security-advisories@github.com

Patch

https://github.com/zauberzeug/nicegui/security/advisories/GHSA-72qc-wxch-74mg

Source: security-advisories@github.com

ExploitVendor Advisory

https://github.com/zauberzeug/nicegui/security/advisories/GHSA-72qc-wxch-74mg

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

ExploitVendor Advisory

Timeline

No history available yet.