CVE-2026-21873

NiceGUI (Python UI framework) has a cross-site scripting risk in versions 2.22.0–3.4.1 due to an unsafe pushstate listener in ui.sub_pages that lets an attacker manipulate the URL fragment via an iframe. The issue is exploitable without user interaction and affects pages embeddable in iframes. A ...

CVE-2026-21873: Improper Neutralization of Input During Web Page Generation

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.subpages 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...

CVE-2026-21872: Improper Neutralization of Input During Web Page Generation

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.subpages, 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 versi...