CVE-2026-2878: Progress Telerik UI For ASP.NET AJAX

Medium severity, CVSS 5.9. EPSS: 0.3% chance of exploitation in the next 30 days.

In Progress® Telerik® UI for AJAX, versions prior to 2026.1.225, an insufficient entropy vulnerability exists in RadAsyncUpload, where a predictable temporary identifier, based on timestamp and filename, can enable collisions and file content tampering.

Affected products

• Progress Telerik UI For ASP.NET AJAX: before 2026.1.225 (fixed in 2026.1.225)

Published 2026-02-25. Last modified 2026-06-17.