CVE-2026-6023: Progress Telerik UI For ASP.NET AJAX

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

In Progress® Telerik® UI for AJAX versions 2024.4.1114 through 2026.1.421, the RadFilter control is vulnerable to insecure deserialization when restoring filter state if the state is exposed to the client. If an attacker tampers with this state, a server-side remote code execution is possible.

Affected products

• Progress Telerik UI For ASP.NET AJAX: from 2024.4.1114, before 2026.1.421 (fixed in 2026.1.421)

Published 2026-04-22. Last modified 2026-06-17.