# CVE-2026-124699: Telerik UI for WinForms code generation vulnerability

Source: https://junglewise.ai/threats/cve-2026-124699-in-telerik-ui-for-winforms-versions-prior-to-2026-4-1111-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-12. Updated: 2026-11-12  
License: CC BY 4.0 with a link back

CVE-2026-124699 · Severity: high · CVSS 7.8 · Published 2026-11-12

Telerik UI for WinForms is a toolkit for building Windows desktop applications. A vulnerability in versions before 2026.4.1111 allows attackers to supply malicious expressions that execute arbitrary code within the application, potentially compromising any system running an affected version. An attacker could gain full control of the application and the data it processes.

Technologies: [Progress Telerik UI for WinForms](https://junglewise.ai/threats/technologies/telerik-ui-for-winforms). Vendors: [Progress](https://junglewise.ai/threats/vendors/progress).

## Quick answers

**Is CVE-2026-124699 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-124699 being exploited in the wild.

**How severe is CVE-2026-124699?** High severity, with a CVSS score of 7.8, published 12 November 2026.

**Which products and versions are affected?** Progress Telerik UI for WinForms prior to 2026.4.1111.

**Is there a fix for CVE-2026-124699?** Yes: fixed in 2026.4.1111. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-124699 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-124699?** Check whether you run Progress Telerik UI for WinForms at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 2026.4.1111

## Technical details

An improper control of code generation vulnerability (CWE-94) in Telerik UI for WinForms allows an attacker to inject crafted expressions that are executed as code within the application context. The vulnerability is in the expression evaluation mechanism and requires no special authentication or network access. A successful exploit results in arbitrary code execution with the privileges of the affected application.

## Affected products

- Progress Telerik UI for WinForms prior to 2026.4.1111

## Timeline

- 2026-11-12: disclosed

## References

- [https://www.telerik.com/products/winforms/documentation/knowledge-base/kb-security-improper-control-of-generation-of-code-cve-2026-124699](https://www.telerik.com/products/winforms/documentation/knowledge-base/kb-security-improper-control-of-generation-of-code-cve-2026-124699)

## Related threats

- [Telerik UI for WinForms untrusted URL redirection](https://junglewise.ai/threats/cve-2026-124700-in-telerik-ui-for-winforms-versions-prior-to-2026-4-1111-an)
- [Telerik UI for WinForms deserialization of untrusted data](https://junglewise.ai/threats/cve-2026-124701-in-telerik-ui-for-winforms-versions-prior-to-2026-4-1111-a)