CVE-2026-106157 in Kendo UI for jQuery
Summary
by MITRE • 10/15/2026
In Progress® Kendo® UI for jQuery versions starting with 2019.2.514 and prior to 2026.3.1015, the PanelBar component inserts data source item URL values into a single-quoted href attribute without proper encoding. An attacker who can control an item URL can inject additional HTML attributes, including event handlers, and execute JavaScript in a user's browser when the affected item is interacted with. 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 within the PanelBar component across versions from 2019.2.514 up to but not including 2026.3.1015, represents a classic instance of Cross-Site Scripting (XSS) resulting from insufficient input validation and output encoding. The core technical flaw lies in how the PanelBar component handles data source item URLs when rendering them into HTML anchor elements. Specifically, these URL values are inserted directly into single-quoted href attributes without undergoing proper character escaping or sanitization processes. This lack of rigorous encoding allows an attacker who has control over the input data to break out of the intended attribute context and inject arbitrary HTML content.
From a technical perspective, this vulnerability aligns with CWE-79, which describes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. The specific mechanism involves breaking out of the single-quote delimited string within the href attribute. By injecting payloads such as ' onmouseover=alert(1) or similar event handlers, an attacker can cause the browser to interpret these injected strings not merely as part of a URL but as executable JavaScript code associated with DOM events. This exploitation technique is categorized under ATT&CK Tactic TA0005 Defense Evasion and specifically maps to techniques like Client-side Scripting Injection (T1189) or potentially Cross-Site Scripting: Stored if the malicious data persists in the application's backend storage before being served to victims.
The operational impact of this vulnerability is significant, particularly for applications that rely on dynamic content loading within their navigation structures. If an attacker can manipulate the data source feeding into the PanelBar component, they can execute arbitrary JavaScript code in the context of any user who interacts with the compromised menu item. This interaction triggers the event handlers embedded in the malicious payload. The consequences extend beyond mere script execution; successful exploitation compromises both the confidentiality and integrity of sensitive data accessible to the affected application. Attackers can steal session cookies, perform actions on behalf of authenticated users, or redirect victims to phishing sites, thereby undermining trust in the web application's security posture.
Mitigation strategies must focus on addressing the root cause: improper output encoding. Developers should ensure that all dynamic content inserted into HTML attributes is properly encoded according to the context. In this case, since the data is placed within a single-quoted attribute value, specific attention must be paid to escaping single quotes and other special characters that could facilitate tag or attribute injection. Utilizing built-in templating engines or security libraries provided by the Kendo UI framework can help automate these encoding processes. Furthermore, implementing Content Security Policy (CSP) headers can serve as an effective defense-in-depth measure by restricting the sources from which scripts are allowed to execute, thereby mitigating the impact of any successfully injected script even if input validation fails.
The vendor has addressed this issue in version 2026.3.1015 and later releases. Organizations utilizing Progress Kendo UI for jQuery must upgrade their dependencies immediately to patched versions that implement proper encoding mechanisms within the PanelBar component's rendering logic. Regular security audits of third-party library usage are recommended to ensure that such vulnerabilities do not persist in legacy codebases or unpatched environments, maintaining a robust defense against client-side injection attacks.