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jQuery integration with Telerik UI for ASP.NET AJAX

Updated on Feb 18, 2026

This help article describes the integration of jQuery with Telerik® UI for ASP.NET AJAX library and its security.

Embedded jQuery

Telerik® UI for ASP.NET AJAX library is shipped with custom jQuery 1.12.4 embedded in the Assembly and it is automatically loaded by UI components (e.g. RadAvatar, RadButton, RadComboBox, etc..).

The embedded jQuery in Telerik library contains fixes for the known vulnerabilities (see Embedded jQuery Security) and is secure. In case, however, you prefer to use a newer version, feel free to include your own following the instructions from Including external jQuery section.

Once loaded, the jQuery instance will be available in the globals, e.g. window.jQuery and window.$.

Example

ASP.NET

<script>
  // jQuery alias in Globals
  $(document).ready(function () { /* your code */ });

  jQuery(document).ready(function () { /* your code */ });
</script>

In Telerik versions before 2026 Q1 jQuery is available in the $telerik namespace.

Example

ASP.NET

<script>
  $telerik.$(document).ready(function () { /* your code */ });
  
  // You can also create an alias referencing the jQuery from $telerik namespace
  var $ = window.jQuery = window.$ = $telerik.$;
  // then use it like this
  $(document).ready(function () { /* your code */ });
  jQuery(document).ready(function () { /* your code */ });
</script>

You can also load jQuery without the need to add Telerik UI components on the page by referencing the required scripts.

Example

ASP.NET

<telerik:RadScriptManager ID="RadScriptManager1" runat="server" EnableEmbeddedjQuery="false">
    <Scripts>
        <%-- Dependency for jQuery --%>
        <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.Core.js" />
        <%-- Embedded jQuery 1.12.4 --%>
        <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.jQuery.js" />
    </Scripts>
</telerik:RadScriptManager>

Embedded jQuery Security

The embedded jQuery comes with backport fixes for the known vulnerabilities.

Vulnerabilities fixed in the custom jQuery 1.12.4 embedded in the Telerik.Web.UI assembly:

Vulnerability	Description	Telerik UI for ASP.NET AJAX Version
CVE-2020-11022 CVE-2020-11023	Potential XSS vulnerability in jQuery before 3.5.0	Fixed in R2 2020
CVE-2019-11358	jQuery before 3.4.0 Object.prototype Pollution via extend(true) in Drupal, Backdrop CMS, and Others	Fixed in R1 2019
CVE-2015-9251	jQuery before 3.0.0 Cross-domain Ajax Request XSS Vulnerability via Missing dataType Option	Fixed in R1 2019

You can find more information in the following KB article on the matter: Vulnerabilities of jQuery versions embedded and fixed in UI for ASP.NET AJAX.

Embedded jQuery Version History in Telerik library

Telerik® UI for ASP.NET AJAX Version	jQuery Version	Remarks
R1 2019 - present	1.12.4	Uses a modified jQuery version 1.12.4 that includes security vulnerability backport fixes. Find more info in the Embedded jQuery Security section.
R2 2018 SP1 - R3 2018	1.12.4	Downgraded from 3.3.1 due to incompatibilities with the MS AJAX framework and its __doPostBack() method - see more
R2 2018	3.3.1.	It has known issues and we recommend using R2 2018 SP1.
Q3 2014 - R1 2018	1.11.1
Q1 2013 SP1 - Q2 2014 SP1	1.9.1
Q1 2012 SP1 - Q1 2013	1.7.2
Q3 2011 SP1 Q1 2012	1.7.1
Q2 2011 SP1 Q3 2011	1.6.4
Q2 2011	1.6.2
Q1 2011 SP1 SP2	1.5.2
Q1 2011	1.5.1
Q3 2010 SP1 Q3 2010 SP2	1.4.4
Q3 2010	1.4.3
Q1 2010 Q2 2010	1.4.2
Q1 2009 Q2 2009	1.3.2

Including External jQuery

jQuery 4.0.0 removed a few APIs Telerik components rely on, this version will not work.

For Telerik versions before 2026 Q1, please follow the instructions from the Include external jQuery for Telerik prior to version 2026 Q1 article.

To include an external jQuery, you will need to:

Use the telerik:RadScriptManager (will not work with standard asp:ScriptManager)
Disable the Embedded jQuery through the EnableEmbeddedjQuery property.
Provide the URL or path of the external jQuery through the ExternaljQueryUrl property.
- https://code.jquery.com/jquery-3.7.1.min.js - Web/CDN hosted URL (also check External jQuery Security)
- ~/Scripts/jquery-3.7.1.min.js - Path to the file in your project

Example

ASP.NET

<telerik:RadScriptManager ID="RadScriptManager1" runat="server"
  EnableEmbeddedjQuery="false"
  ExternaljQueryUrl="https://code.jquery.com/jquery-3.7.1.min.js">
</telerik:RadScriptManager>

You can also set these options in the web.config file to apply the changes glboally rather than per page in your app.

web.config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <appSettings>
    <add key="Telerik.ScriptManager.EnableEmbeddedjQuery" value="false"/>
    <add key="Telerik.ScriptManager.ExternaljQueryUrl" value="https://code.jquery.com/jquery-3.7.1.min.js"/>
  </appSettings>
</configuration>

For each Telerik version, there is a minimum required jQuery that can be used (see Embedded jQuery Version History in Telerik library). Please ensure that the jQuery version is greater than or equal to the required version.

External jQuery Security

Starting from 2026 Q1, the external jQuery script you specify is handled by a Telerik Handler to ensure the correct load order and initialization of the script. The handler adds a layer of security by only allowing jQuery scripts from from Trusted sources.

By default the following CDN sources are allowed:

code.jquery.com
ajax.googleapis.com
cdnjs.cloudflare.com
cdn.jsdelivr.net
ajax.aspnetcdn.com

If the jQuery library you would like to link is hosted on a different site, you can extend the Trusted CDN hosts by setting the Telerik.ExternaljQuery.TrustedHosts key in the web.config <appSettings>.

Example

web.config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <appSettings>
    <!-- You can specify multiple hosts separated by comma -->
    <add key="Telerik.ExternaljQuery.TrustedHosts" value="intranet.mycompany.corp, another.location.org"/>
  </appSettings>
</configuration>