CVE-2026-13187 in Telerik UI for ASP.NET AJAX
Summary
by MITRE • 07/22/2026
In Progress® Telerik® UI for AJAX prior to v2026.2.708, DialogHandler provider type input may be tampered with, potentially altering dialog processing and enabling chained exploitation.
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Analysis
by VulDB Data Team • 07/22/2026
The vulnerability in Progress Telerik UI for AJAX prior to version 2026.2.708 resides in the DialogHandler provider type input which lacks proper validation mechanisms, creating a potential security risk that could allow attackers to manipulate dialog processing behavior. This flaw represents a critical issue in the application's input sanitization and validation controls, where untrusted data from the DialogHandler provider type is not adequately verified before being processed within the application's dialog handling framework. The vulnerability stems from insufficient type checking and validation of provider inputs, which could enable malicious actors to inject altered or malicious data that affects how dialogs are rendered or processed within the Telerik UI components.
The technical exploitation of this vulnerability involves manipulating the provider type input that controls dialog behavior, potentially allowing attackers to alter the execution flow or modify dialog processing logic. This type of vulnerability falls under CWE-20, which describes improper input validation, and could enable attackers to perform unauthorized actions through manipulation of the dialog handler's provider type parameter. The flaw creates a pathway for chained exploitation where initial manipulation of the dialog processing can lead to more severe security consequences, potentially allowing privilege escalation or information disclosure through cascading effects within the application's AJAX framework.
The operational impact of this vulnerability extends beyond simple dialog manipulation as it could enable attackers to compromise the integrity of user interactions within applications that utilize Telerik UI components. When an attacker successfully exploits this flaw, they can potentially alter how dialogs are processed, leading to unauthorized access to sensitive data or functionality. The vulnerability affects web applications built using Telerik UI for AJAX framework where dialog handlers are utilized, creating a risk that could be exploited in various attack scenarios including cross-site scripting attacks, session manipulation, or even remote code execution depending on the application's broader security architecture and implementation practices.
Organizations using affected versions of Progress Telerik UI for AJAX should implement immediate mitigations including updating to version 2026.2.708 or later which contains the necessary patches to address the input validation issues in the DialogHandler provider type. Additionally, implementing proper input validation controls at multiple layers of the application architecture can help prevent exploitation attempts, including validating all provider type inputs before processing and implementing proper access controls for dialog handling components. Security teams should also consider monitoring for unusual patterns in dialog handler usage that might indicate attempted exploitation of this vulnerability.
The vulnerability demonstrates a classic example of insufficient validation in web application frameworks and aligns with ATT&CK technique T1059.007 for input validation weaknesses. Organizations should review their implementation practices to ensure that all user-provided inputs, particularly those controlling application behavior or component instantiation, undergo proper sanitization and validation checks. This includes implementing strict type checking mechanisms and ensuring that provider types are validated against expected values before being processed, thereby preventing attackers from manipulating the dialog handling pipeline through malicious input injection. The remediation approach should include both immediate patching of the vulnerable component and long-term architectural improvements to prevent similar vulnerabilities in other parts of the application's AJAX framework components.