Cyber Resilience

CVE-2026-6022

HighDDoS

Published: 22 April 2026

Published
22 April 2026
Modified
05 May 2026
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0011 29.8th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-6022 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Progress Telerik Ui For Asp.Net Ajax. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 29.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability).

Deeper analysis

CVE-2026-6022 is an uncontrolled resource consumption vulnerability (CWE-400) in the RadAsyncUpload component of Progress® Telerik® UI for AJAX versions prior to 2026.1.421. The issue arises from a lack of cumulative size enforcement during chunk reassembly, allowing uploaded files to exceed configured maximum size limits. This can lead to disk space exhaustion on affected systems. The vulnerability has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating high availability impact with no requirements for privileges or user interaction.

Attackers can exploit this vulnerability remotely over the network with low complexity. Any unauthenticated user who can reach an affected RadAsyncUpload endpoint may send specially crafted chunked upload requests that bypass per-chunk size checks, resulting in excessive disk usage and potential denial-of-service through resource exhaustion. Successful exploitation requires no special privileges or user interaction, making it accessible to remote attackers.

Telerik has published a knowledge base article detailing the issue at https://www.telerik.com/products/aspnet-ajax/documentation/knowledge-base/kb-security-uncontrolled-resource-consumption-cve-2026-6022. Mitigation involves updating to Telerik UI for AJAX 2026.1.421 or later, which enforces proper cumulative size limits during chunk reassembly. Security practitioners should verify deployments, apply patches promptly, and consider network-level upload restrictions as interim measures.

EU & UK References

Vulnerability details

In Progress® Telerik® UI for AJAX prior to 2026.1.421, RadAsyncUpload contains an uncontrolled resource consumption vulnerability that allows file uploads to exceed the configured maximum size due to missing cumulative size enforcement during chunk reassembly, leading to disk space exhaustion.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Vulnerability directly enables remote exploitation of a public-facing application component to cause excessive disk resource consumption and denial of service via application or system exploitation.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2026-6023Same product: Progress Telerik Ui For Asp.Net Ajax
CVE-2025-1758Same vendor: Progress
CVE-2026-8485Same vendor: Progress
CVE-2026-8488Same vendor: Progress
CVE-2024-56921Shared CWE-400
CVE-2026-21945Shared CWE-400
CVE-2024-33618Shared CWE-400
CVE-2025-9278Shared CWE-400
CVE-2026-41135Shared CWE-400
CVE-2026-20650Shared CWE-400

Affected Assets

progress
telerik ui for asp.net ajax
≤ 2026.1.421

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Flaw remediation requires updating Telerik UI for AJAX to 2026.1.421 or later, which enforces cumulative size limits during chunk reassembly to prevent disk space exhaustion.

prevent

Denial-of-service protection implements mechanisms to limit effects of resource exhaustion attacks from oversized chunked file uploads.

prevent

Resource availability employs allocation mechanisms to protect disk space from unauthorized consumption by bypassing per-chunk size limits.

References