CVE-2019-18935VulnerabilityPublished 11/03/2021Updated 10/24/2026

CVE-2019-18935: Progress Telerik UI for ASP.NET AJAX Deserialization of Untrusted Data Vulnerability

Affects Progress Telerik UI for ASP.NET AJAXSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 11/03/2021
KEV deadline: 05/03/2022
Ransomware: Used in ransomware campaigns
EPSS: 99.7% chance of exploitation in 30 days – higher than 99% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2019-18935 (opens in a new tab)

Description

CVE-2019-18935 is a deserialization of untrusted data vulnerability in Progress Telerik UI for ASP.NET AJAX, specifically through the RadAsyncUpload component. This flaw allows remote code execution on the server within the w3wp.exe process. The vulnerability has been exploited in the wild and is associated with known ransomware campaigns.

Summary

Progress Telerik UI for ASP.NET AJAX contains a deserialization vulnerability (CWE-502) in the RadAsyncUpload component. This vulnerability allows attackers to send crafted serialized data that, when deserialized by the server, leads to arbitrary code execution in the context of the IIS worker process (w3wp.exe). Exploitation of this vulnerability has been observed in the wild, including use in ransomware campaigns, indicating active threat actor interest and impact.

Impact

Successful exploitation results in remote code execution on the affected server, allowing attackers to execute arbitrary code with the privileges of the IIS worker process. This can lead to full system compromise, data theft, or deployment of ransomware.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is confirmed, restrict access to the vulnerable component and monitor for exploitation attempts. Follow vendor guidance once available.

Weaknesses

CWE-502Deserialization of Untrusted Data (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 08:56:50 UTC

Weaknesses

References

Related threats