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CVE-2026-21871GHSA-7GRM-H62G-5M97PYSEC-2026-1698

NiceGUI is vulnerable to XSS via Unescaped URL in ui.navigate.history.push() / replace()

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 3.5.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: no
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • zauberzeug nicegui

    From 2.13.0 · fixed in 3.5.0

  • niceguiPyPI

    From 2.13.0 · fixed in 3.5.0

References 2

GitHub · zauberzeug/nicegui