{"id":"CVE-2025-66469","aliases":["GHSA-72qc-wxch-74mg","PYSEC-2026-1697"],"url":"https://o3.security/vulnerability/CVE-2025-66469","summary":"NiceGUI Reflected XSS in ui.add_css, ui.add_scss, and ui.add_sass via Style Injection","details":"NiceGUI is a Python-based UI framework. Versions 3.3.1 and below are vulnerable to Reflected XSS through its ui.add_css, ui.add_scss, and ui.add_sass functions. The functions lack proper sanitization or encoding for the JavaScript context they generate. An attacker can break out of the intended <style> or <script> tags by injecting closing tags (e.g., </style> or </script>), allowing for the execution of arbitrary JavaScript. This issue is fixed in version 3.4.0.","published":"2025-12-08T23:54:37.955Z","modified":"2026-08-08T03:32:26.863739492Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"nicegui","fixedVersion":"3.4.0"}],"fix":{"url":"https://github.com/zauberzeug/nicegui/commit/a8fd25b7d5e23afb1952d0f60a1940e18b5f1ca8","label":"zauberzeug/nicegui@a8fd25b"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66469.json"},{"type":"ADVISORY","url":"https://github.com/zauberzeug/nicegui/security/advisories/GHSA-72qc-wxch-74mg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-66469"},{"type":"FIX","url":"https://github.com/zauberzeug/nicegui/commit/a8fd25b7d5e23afb1952d0f60a1940e18b5f1ca8"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-08T03:32:26.863739492Z"}}