Deserialization of Untrusted Data Vulnerability in Telerik UI for ASP.NET AJAX

published 2026-04-22 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-24632

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

Progress Software Telerik UI for ASP.NET AJAX 2026.1.421

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 6 mo ago (2026-04-22)

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Progress Software Telerik UI for ASP.NET AJAX

Classification

Weakness

CWE-502 Deserialization of Untrusted Data

References

telerik.com /products/aspnet-ajax/documentation/knowledge-base/kb-security-deserialization-of-untrusted-data-cve-2026-6023
vendor-advisory, mitigation

Sources

CVE List CVE-2026-6023
NVD CVE-2026-6023

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary