RadAsyncUpload Default HMAC Key Fallback Vulnerability in Telerik UI for ASP.NET AJAX

published 2026-07-22 3 mo ago modified 2026-10-24 16 d ago also EUVD-2026-47689

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits: 0; none known

In Progress® Telerik® UI for AJAX prior to v2026.2.708, when Telerik.Upload.ConfigurationHashKey is absent and machineKey is not explicitly configured, upload metadata integrity protection may fall back to a predictable default key, enabling attackers to forge protected upload metadata and unlock further exploit chains.

Patch / fix

fixed in 1

Progress Software Telerik UI for ASP.NET AJAX 2026.2.708

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 3 mo ago (2026-07-22)

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

Progress Software Telerik UI for ASP.NET AJAX

Classification

Weakness

CWE-321 Use of Hard-coded Cryptographic Key

References

telerik.com /products/aspnet-ajax/documentation/knowledge-base/kb-security-rau-unauth-deserialization-chain-cve-2026-13184
vendor-advisory, mitigation

Sources

CVE List CVE-2026-13184
NVD CVE-2026-13184

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary