Zero-click XSS in all NiceGUI apps which uses `ui.sub_pages`_CVE-2026-21873

{
    "lastseen": "",
    "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.",
    "published": "2026-01-08T09:50:23.361Z",
    "modified": "2026-01-08T09:50:23.361Z",
    "type": "cve",
    "title": "Zero-click XSS in all NiceGUI apps which uses `ui.sub_pages`",
    "source": "GitHub_M",
    "references": "https://github.com/zauberzeug/nicegui/security/advisories/GHSA-mhpg-c27v-6mxr\nhttps://github.com/zauberzeug/nicegui/releases/tag/v3.5.0",
    "id": "CVE-2026-21873",
    "bulletinFamily": "",
    "cwe": [
        "CWE-79"
    ],
    "cvelist": null,
    "sourceData": "zauberzeug nicegui >= 2.22.0, < 3.5.0",
    "sourceHref": "",
    "cvss": {
        "score": 7.2,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "nicegui",
    "version": ">= 2.22.0, < 3.5.0",
    "vendor": "zauberzeug",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}