CVE-2026-21872 — NiceGUI apps are vulnerable to XSS which uses `ui.sub_pages` and render arbitrary user-provided links

CVE-2026-21872

NiceGUI apps are vulnerable to XSS which uses `ui.sub_pages` and render arbitrary user-provided links PUBLISHED

Description (CNA)

NiceGUI is a Python-based UI framework. From versions 2.22.0 to 3.4.1, an unsafe implementation in the click event listener used by ui.sub_pages, combined with attacker-controlled link rendering on the page, causes XSS when the user actively clicks on the link. This issue has been patched in version 3.5.0.

Affected (CNA)

Vendor / product	Versions
zauberzeug / nicegui	affected >= 2.22.0, < 3.5.0

CWE

CWE-79

References

https://github.com/zauberzeug/nicegui/security/advisories/GHSA-m7j5-rq9j-6jj9
https://github.com/zauberzeug/nicegui/releases/tag/v3.5.0

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.