CVE-2025-66470
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk16th percentile - higher than 16% of all known CVEs
Summary
NiceGUI is a Python-based UI framework. Versions 3.3.1 and below are subject to an XSS vulnerability through the ui.interactive_image component, which renders SVG content using Vue's v-html directive without any sanitization. An attacker can inject malicious HTML or JavaScript via the SVG <foreignObject> tag whenever the image component is rendered or updated.
Risk Assessment
This is particularly dangerous for dashboards or multi-user applications displaying user-generated content or annotations, where an attacker could execute malicious code in the victim's browser.
Recommendation
Update NiceGUI to version 3.4.0, which fixes this vulnerability.
Other vulnerabilities in NiceGUI
See all- CVE-2026-21873High
NiceGUI versions 2.22.0 to 3.4.1 have an unsafe implementation in the pushstate event listener used by ui.sub_pages, allowing an attacker to manipulate the fragment identifier of the URL, even cross-site, using an iframe. This issue has been patched in version 3.5.0.
- CVE-2026-45554Medium
NiceGUI is a Python-based UI framework. Prior to version 3.12.0, two FastAPI routes that serve per-component static assets in NiceGUI accept a sub-path parameter that may resolve to a directory rather than a file. Requests that resolve to a directory raise an unhandled RuntimeError inside Starlette's FileResponse, which Uvicorn writes to the server log as a full traceback. Because the routes are reachable without authentication, a remote attacker can amplify log volume and consume disk and log-pipeline capacity on any publicly reachable NiceGUI server. This issue has been patched in version 3.12.0.
- CVE-2026-45553High
NiceGUI prior to version 3.12.0 has a vulnerability in ui.restructured_text() that renders reStructuredText server-side without disabling file insertion directives. An attacker can read local files accessible to the NiceGUI server process.
- CVE-2026-39844Medium
NiceGUI, a Python-based UI framework, prior to version 3.10.0 is vulnerable to arbitrary file write on Windows. Because PurePosixPath only recognizes forward slashes (/) as path separators, an attacker can bypass sanitization by using backslashes (\) in the upload filename.
Original NVD description (English source)
NiceGUI is a Python-based UI framework. Versions 3.3.1 and below are subject to a XSS vulnerability through the ui.interactive_image component of NiceGUI. The component renders SVG content using Vue's v-html directive without any sanitization. This allows attackers to inject malicious HTML or JavaScript via the SVG <foreignObject> tag whenever the image component is rendered or updated. This is particularly dangerous for dashboards or multi-user applications displaying user-generated content or annotations. This issue is fixed in version 3.4.0.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS