dbcve.org
Telerik Ui For Asp.net AjaxApplication · Progress

CVE-2026-6022

HIGH · 7.5 CVSS v3.1 Published 2026-04-22
Fix available
A fix is available. Upgrade to 2026.1.421 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The RadAsyncUpload component in Telerik UI for AJAX versions prior to 2026.1.421 lacks cumulative size validation during chunk-based file uploads. When files are uploaded in fragments, each chunk passes individual size checks, but the total reassembled file size is not validated against configured limits, allowing attackers to exhaust disk space by uploading oversized files.

MitigationUpgrade to Telerik UI for AJAX version 2026.1.421 or later which implements cumulative size enforcement. Additionally, configure server-level upload size limits at the IIS or application level as a defense-in-depth measure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Telerik Ui For Asp.net AjaxApplication
Affected:< 2026.1.421

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Telerik UI for AJAX version
    Check the Telerik.Web.UI.dll assembly version in the application's bin folder, or look in the packages.config/NuGet package reference for Telerik.UI.for.AspNet.Ajax, or examine the web.config assembly binding redirect
    Affected if The version number is lower than 2026.1.421 (for example, 2025.x, 2024.x, or earlier)
  2. Verify RadAsyncUpload component is in use
    Search the codebase for RadAsyncUpload declarations in .aspx, .ascx, or .master files, or check web.config for RadAsyncUpload handler registration under system.web.httpHandlers
    Affected if RadAsyncUpload is implemented and handles file uploads in the application
  3. Confirm chunk-based upload is enabled
    Check the RadAsyncUpload configuration in web.config or the aspx page markup for EnableChunkUpload="true" or similar chunking settings, or review the Telerik UI upload settings for chunk size configuration
    Affected if Chunk upload is enabled (this is the upload mode where the vulnerability applies)
  4. Review configured upload size limits
    Examine web.config for maxRequestLength and uploadReadAheadSize settings in system.web, and check Telerik-specific upload settings such as MaxFileSize or FileSizeThreshold
    Affected if No cumulative size limit is configured for the reassembled file, or only per-chunk limits exist without total file size validation

You are affected if your Telerik UI for AJAX version is below 2026.1.421 AND the RadAsyncUpload component is actively handling chunk-based file uploads in your application.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2026.1.421 or later
Fixed in 2026.1.421
Interim mitigation

Upgrade to Telerik UI for AJAX version 2026.1.421 or later which implements cumulative size enforcement. Additionally, configure server-level upload size limits at the IIS or application level as a defense-in-depth measure.

Recommended fix High confidence

Upgrade to Telerik UI for ASP.NET AJAX version 2026.1.421

  1. Download Telerik UI for ASP.NET AJAX version 2026.1.421 or later from the official Telerik website (www.telerik.com)
  2. Review the release notes for version 2026.1.421 to understand the changes and any known issues
  3. Backup your current project and all Telerik UI for ASP.NET AJAX assemblies
  4. Replace the existing Telerik.Web.UI.dll and related assemblies with the new version from 2026.1.421
  5. Rebuild and test your application to ensure the upload functionality works correctly with the new version
  6. Verify that the maximum file size configuration is properly enforced for chunked uploads
Caveat Review Telerik release notes for any breaking changes between your current version and 2026.1.421

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Telerik Ui For Asp.net Ajax Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA3.0 h
19.0 hours of engineering $3,380
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,408.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-6022 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-6022 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data