Vulnerability · Published Feb 25, 2026 · Assigned by ProgressSoftware
CVE-2026-2878Insufficient Entropy Vulnerability in Telerik UI for ASP.NET AJAX
Medium 5.3
In plain English
A medium-severity security flaw in Telerik UI for ASP.NET AJAX from Progress Software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).
Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.2%top 88.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Progress Software | Telerik UI for ASP.NET AJAX | 2011.2.712 – before 2026.1.225 |
Weakness: CWE-331 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N