Description

NiceGUI is a Python-based UI framework. From versions 2.13.0 to 3.4.1, there is a XSS risk in NiceGUI when developers pass attacker-controlled strings into ui.navigate.history.push() or ui.navigate.history.replace(). These helpers are documented as History API wrappers for updating the browser URL without page reload. However, if the URL argument is embedded into generated JavaScript without proper escaping, a crafted payload can break out of the intended string context and execute arbitrary JavaScript in the victim’s browser. Applications that do not pass untrusted input into ui.navigate.history.push/replace are not affected. This issue has been patched in version 3.5.0.

INFO

Published Date :

2026-01-08T09:49:55.136Z

Last Modified :

2026-01-08T15:15:16.509Z

Source :

GitHub_M
AFFECTED PRODUCTS

The following products are affected by CVE-2026-21871 vulnerability.

Vendors Products
Zauberzeug
  • Nicegui
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-21871.

URL Resource
https://github.com/zauberzeug/nicegui/releases/tag/v3.5.0 cve-icon cve-icon
https://github.com/zauberzeug/nicegui/security/advisories/GHSA-7grm-h62g-5m97 cve-icon cve-icon
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CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact