Medium severity · published Feb 25, 2026
CVE-2026-2878
Insufficient Entropy Vulnerability in Telerik UI for ASP.NET AJAX
5.9
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 11% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TU
Telerik UI for ASP.NET AJAX · Progress Software
2011.2.712 before 2026.1.225 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-2878
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-2878
Mitigation
https://www.telerik.com/products/aspnet-ajax/documentation/knowledge-base/kb-security-insufficient-entropy-cve-2026-2878
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