Falko Schindler

8 exploits Active since Apr 2024
CVE-2026-39844 WRITEUP MEDIUM WRITEUP
NiceGUI <3.10.0 Windows Upload Filename - Path Traversal
NiceGUI is a Python-based UI framework. Prior to 3.10.0, Since PurePosixPath only recognizes forward slashes (/) as path separators, an attacker can bypass this sanitization on Windows by using backslashes (\) in the upload filename. Applications that construct file paths using file.name (a pattern demonstrated in NiceGUI's bundled examples) are vulnerable to arbitrary file write on Windows. This vulnerability is fixed in 3.10.0.
CVSS 5.9
CVE-2026-33332 WRITEUP HIGH WRITEUP
NiceGUI's unvalidated chunk size parameter in media routes can cause memory exhaustion
NiceGUI is a Python-based UI framework. Prior to version 3.9.0, NiceGUI's app.add_media_file() and app.add_media_files() media routes accept a user-controlled query parameter that influences how files are read during streaming. The parameter is passed to the range-response implementation without validation, allowing an attacker to bypass chunked streaming and force the server to load entire files into memory at once. With large media files and concurrent requests, this can lead to excessive memory consumption, degraded performance, or denial of service. This issue has been patched in version 3.9.0.
CVSS 7.5
CVE-2026-27156 WRITEUP MEDIUM WRITEUP
NiceGUI < 3.8.0 - Cross-Site Scripting via Element Method Execution
NiceGUI is a Python-based UI framework. Prior to version 3.8.0, several NiceGUI APIs that execute methods on client-side elements (`Element.run_method()`, `AgGrid.run_grid_method()`, `EChart.run_chart_method()`, and others) use an `eval()` fallback in the JavaScript-side `runMethod()` function. When user-controlled input is passed as the method name, an attacker can inject arbitrary JavaScript that executes in the victim's browser. Additionally, `Element.run_method()` and `Element.get_computed_prop()` used string interpolation instead of `json.dumps()` for the method/property name, allowing quote injection to break out of the intended string context. Version 3.8.0 contains a fix.
CVSS 6.1
CVE-2024-32005 WRITEUP HIGH WRITEUP
NiceGUI <1.4.21 - Local File Inclusion
NiceGUI is an easy-to-use, Python-based UI framework. A local file inclusion is present in the NiceUI leaflet component when requesting resource files under the `/_nicegui/{__version__}/resources/{key}/{path:path}` route. As a result any file on the backend filesystem which the web server has access to can be read by an attacker with access to the NiceUI leaflet website. This vulnerability has been addressed in version 1.4.21. Users are advised to upgrade. There are no known workarounds for this vulnerability.
CVSS 8.2
CVE-2025-53354 WRITEUP MEDIUM WRITEUP
NiceGUI < 3.0.0 - Cross-Site Scripting via ui.html()
NiceGUI is a Python-based UI framework. Versions 2.24.2 and below are at risk for Cross-Site Scripting (XSS) when developers render unescaped user input into the DOM using ui.html(). NiceGUI did not enforce HTML or JavaScript sanitization, so applications that directly combine components like ui.input() with ui.html() or ui.chat_message with HTML content without escaping may allow attackers to execute arbitrary JavaScript in the user’s browser. Applications that do not pass untrusted input into ui.html() are not affected. This issue is fixed in version 3.0.0.
CVSS 6.1
CVE-2025-66469 WRITEUP MEDIUM WRITEUP
NiceGUI < 3.4.0 - Reflected Cross-Site Scripting via CSS/SCSS/SASS Injection
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.
CVSS 6.1
CVE-2026-21874 WRITEUP MEDIUM WRITEUP
NiceGUI 2.10.0-3.4.1 - Unauthenticated Resource Exhaustion via Redis Connection Leak
NiceGUI is a Python-based UI framework. From versions v2.10.0 to 3.4.1, an unauthenticated attacker can exhaust Redis connections by repeatedly opening and closing browser tabs on any NiceGUI application using Redis-backed storage. Connections are never released, leading to service degradation when Redis hits its connection limit. NiceGUI continues accepting new connections - errors are logged but the app stays up with broken storage functionality. This issue has been patched in version 3.5.0.
CVSS 5.3
CVE-2026-25516 WRITEUP MEDIUM WRITEUP
NiceGUI < 3.7.0 - Stored Cross-Site Scripting via ui.markdown() Component
NiceGUI is a Python-based UI framework. The ui.markdown() component uses the markdown2 library to convert markdown content to HTML, which is then rendered via innerHTML. By default, markdown2 allows raw HTML to pass through unchanged. This means that if an application renders user-controlled content through ui.markdown(), an attacker can inject malicious HTML containing JavaScript event handlers. Unlike other NiceGUI components that render HTML (ui.html(), ui.chat_message(), ui.interactive_image()), the ui.markdown() component does not provide or require a sanitize parameter, leaving applications vulnerable to XSS attacks. This vulnerability is fixed in 3.7.0.
CVSS 6.1