CVE-2026-21873 - Zero-click XSS in all NiceGUI apps which uses `ui.sub_pages`
CVE ID : CVE-2026-21873
Published : Jan. 8, 2026, 10:15 a.m. | 3 hours, 44 minutes ago
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.
Severity: 7.2 | HIGH
Visit the link for more details, such as CVSS details, affected products, timeline, and more...
Published : Jan. 8, 2026, 10:15 a.m. | 3 hours, 44 minutes ago
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.
Severity: 7.2 | HIGH
Visit the link for more details, such as CVSS details, affected products, timeline, and more...