zauberzeug NiceGUI up to 3.7.x API cross site scripting

Summaryinfo

A vulnerability was found in zauberzeug NiceGUI up to 3.7.x. It has been rated as problematic. Impacted is an unknown function of the component API. The manipulation leads to cross site scripting. This vulnerability is uniquely identified as CVE-2026-27156. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in zauberzeug NiceGUI up to 3.7.x. This issue affects an unknown function of the component API. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-27156 since 02/18/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

Upgrading to version 3.8.0 eliminates this vulnerability.

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Productinfo

Vendor

• zauberzeug

Name

• NiceGUI

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7

Website

• Product: https://github.com/zauberzeug/nicegui/

CPE 2.3info

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CPE 2.2info

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