CVE-2026-21873

HIGH

NiceGUI 2.22.0-3.4.1 - Cross-Site Scripting via Pushstate Event Listener

Title source: llm
STIX 2.1

Description

NiceGUI is a Python-based UI framework. From versions 2.22.0 to 3.4.1, an unsafe implementation in the pushstate event listener used by ui.sub_pages allows an attacker to manipulate the fragment identifier of the URL, which they can do despite being cross-site, using an iframe. This issue has been patched in version 3.5.0.

References (2)

Core 2
Core References

Scores

CVSS v3 7.2
EPSS 0.0002
EPSS Percentile 6.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (2)
pypi/nicegui 2.22.0 - 3.5.0PyPI
zauberzeug/nicegui 2.22.0 - 3.5.0
Published Jan 08, 2026
Tracked Since Feb 18, 2026