CVE-2026-6023 Deserialization of Untrusted Data Vulnerability in Telerik UI for ASP.NET AJAX

High 8.1 Published 22 Apr 2026 Updated 23 Apr 2026

Attackers can achieve remote code execution by tampering with client-exposed filter state in the RadFilter control.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-6023?

CVE-2026-6023 is a high-severity unsafe deserialization vulnerability in Progress Software Telerik UI for ASP.NET AJAX, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-502

Which versions are affected by CVE-2026-6023?

It affects 1 product.

Products include Progress Telerik Ui for Asp.net Ajax.

How do I fix CVE-2026-6023?

No fix has been published for CVE-2026-6023 yet. Limit exposure of the affected software until one is available.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2026-6023 being exploited?

There is no known exploitation of CVE-2026-6023 in the wild and no public exploit code.

Sources

Also known as GHSA-mcrv-gh25-252c.