CVE-2026-106147 in Kendo UI for jQuery
Summary
by MITRE • 10/15/2026
In Progress® Kendo® UI for jQuery releases starting with R1 2020 and prior to 2026.3.1015, the ListBox default item template renders the bound dataTextField value as raw HTML without encoding. An attacker who can modify the bound data can supply HTML containing event handlers that execute JavaScript in a user's browser when the affected list item is rendered. Successful exploitation can compromise the confidentiality and integrity of data accessible to the affected application. This issue is fixed in version 2026.3.1015.
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Analysis
by VulDB Data Team • 10/15/2026
The vulnerability identified in Progress Kendo UI for jQuery, specifically affecting versions from R1 2020 up to but not including 2026.3.1015, represents a critical server-side input validation failure that manifests as Cross-Site Scripting within the ListBox component's default item template functionality. This issue stems directly from how the framework handles data binding for the dataTextField property. When developers bind external or user-modifiable data sources to this field without implementing strict output encoding mechanisms, the Kendo UI library renders the content of these fields as raw HTML rather than escaping special characters such as angle brackets and quotes. Consequently, any malicious script tags, event handlers like onerror or onload, or other executable JavaScript payloads embedded within the bound text are interpreted directly by the user's web browser during the rendering process. This behavior violates fundamental security principles regarding the separation of code and data, allowing an attacker who has the ability to inject content into the bound dataset to execute arbitrary scripts in the context of the victim’s session.
From a technical perspective, this flaw is classified under CWE-79, which covers Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting (XSS). The specific vector here relies on the application's trust model assuming that data bound to UI components is safe for HTML rendering without explicit sanitization. In many enterprise applications utilizing Kendo UI, list boxes are populated with dynamic content derived from database queries or API responses. If an attacker can manipulate these underlying data sources through weak input validation elsewhere in the application logic, they effectively gain a persistent execution vector within the user interface. The exploitation does not require direct interaction with form inputs but rather depends on the successful injection of malicious payloads into the data layer that feeds the ListBox component. Once rendered, the browser executes the injected JavaScript, granting the attacker full access to DOM elements and potentially session cookies or authentication tokens stored in local storage or cookies associated with the application domain.
The operational impact of this vulnerability is severe, as it compromises both the confidentiality and integrity of sensitive data accessible to the affected application. Successful exploitation allows attackers to perform actions on behalf of legitimate users, steal session identifiers leading to account takeover, deface web pages, or redirect users to malicious sites for phishing attacks. In environments where Kendo UI components are used extensively for complex dashboards or administrative interfaces, this vulnerability can serve as a pivot point for deeper network intrusions if the executed scripts communicate with external command and control servers. The persistence of the issue across multiple major releases highlights a systemic oversight in default configuration settings that prioritize ease of development over security defaults, requiring developers to explicitly opt-in to safer rendering practices rather than having them enabled by default.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The primary solution is to upgrade to version 2026.3.1015 or later, where the vendor has patched this behavior to ensure proper encoding of bound data fields before rendering. For applications that cannot immediately upgrade due to compatibility constraints, developers should implement manual output encoding for any user-supplied data passed to the ListBox's dataTextField property using standard HTML entity encoding techniques such as converting less-than and greater-than symbols into their corresponding entities. Additionally, implementing a Content Security Policy (CSP) header can significantly reduce the impact of successful exploitation by restricting the sources from which scripts are allowed to load and execute. Regular security audits focusing on input validation layers and data binding configurations within Kendo UI components are essential to prevent similar vulnerabilities in other parts of the application stack aligned with OWASP Top 10 guidelines for injection prevention.