PYSEC-2026-1702 NiceGUI apps which use `ui.sub_pages` vulnerable to zero-click XSS

Summary 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. Details The problem is traced as follows: 1. On pushstate, handleStateEvent is...