CVE-2026-21873
7.2 · HIGHOverview
CVE-2026-21873 is a high-severity vulnerability affecting zauberzeug nicegui. It was published on January 8, 2026 and has a CVSS 3.1 base score of 7.2 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.2, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from zauberzeug. Update nicegui to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| zauberzeug | nicegui | >= 2.22.0, < 3.5.0 | Affected |
Frequently Asked Questions
What is CVE-2026-21873?
CVE-2026-21873 is a high-severity vulnerability affecting zauberzeug nicegui. It was published on January 8, 2026 and has a CVSS 3.1 base score of 7.2 (HIGH).
How severe is CVE-2026-21873?
This vulnerability has a CVSS 3.1 base score of 7.2, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-21873?
Check the references section for vendor advisories and patches from zauberzeug. Update nicegui to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-21873?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-21873 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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