# CVE-2019-18935: Progress Telerik UI for ASP.NET AJAX Deserialization of Untrusted Data Vulnerability

> CVE-2019-18935: Progress Telerik UI for ASP.NET AJAX Deserialization of Untrusted Data Vulnerability. CVSS 9.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2019-18935
Last updated: 2025-10-21T23:35:56Z

- Published: 2019-12-11 00:00 UTC · Updated: 2025-10-21 23:35 UTC · Assigner: mitre
- CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 99.7%, 100th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2021-11-03, federal due date 2022-05-03, ransomware use: Known

## Description

Progress Telerik UI for ASP.NET AJAX through 2019.3.1023 contains a .NET deserialization vulnerability in the RadAsyncUpload function. This is exploitable when the encryption keys are known due to the presence of CVE-2017-11317 or CVE-2017-11357, or other means. Exploitation can result in remote code execution. (As of 2020.1.114, a default setting prevents the exploit. In 2019.3.1023, but not earlier versions, a non-default setting can prevent exploitation.)

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Progress: Telerik UI for ASP.NET AJAX

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2019-18935)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2019-18935)
- [http://packetstormsecurity.com/files/155720/Telerik-UI-Remote-Code-Execution.html](http://packetstormsecurity.com/files/155720/Telerik-UI-Remote-Code-Execution.html)
- [http://packetstormsecurity.com/files/159653/Telerik-UI-ASP.NET-AJAX-RadAsyncUpload-Deserialization.html](http://packetstormsecurity.com/files/159653/Telerik-UI-ASP.NET-AJAX-RadAsyncUpload-Deserialization.html)
- [https://codewhitesec.blogspot.com/2019/02/telerik-revisited.html](https://codewhitesec.blogspot.com/2019/02/telerik-revisited.html)
- [https://github.com/bao7uo/RAU\_crypto](https://github.com/bao7uo/RAU_crypto)
- [https://github.com/noperator/CVE-2019-18935](https://github.com/noperator/CVE-2019-18935)
- [https://know.bishopfox.com/research/cve-2019-18935-remote-code-execution-in-telerik-ui](https://know.bishopfox.com/research/cve-2019-18935-remote-code-execution-in-telerik-ui)
- [https://www.bleepingcomputer.com/news/security/us-federal-agency-hacked-using-old-telerik-bug-to-steal-data/](https://www.bleepingcomputer.com/news/security/us-federal-agency-hacked-using-old-telerik-bug-to-steal-data/)
- [https://www.telerik.com/support/kb/aspnet-ajax/details/allows-javascriptserializer-deserialization](https://www.telerik.com/support/kb/aspnet-ajax/details/allows-javascriptserializer-deserialization)
- [https://www.telerik.com/support/whats-new/aspnet-ajax/release-history/ui-for-asp-net-ajax-r1-2020-%28version-2020-1-114%29](https://www.telerik.com/support/whats-new/aspnet-ajax/release-history/ui-for-asp-net-ajax-r1-2020-(version-2020-1-114%29)
- [https://www.telerik.com/support/whats-new/release-history](https://www.telerik.com/support/whats-new/release-history)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2019-18935 · Markdown: https://rewindex.com/cve/CVE-2019-18935.md · JSON: https://rewindex.com/api/v1/cves/CVE-2019-18935 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:48:04.817Z