# CVE-2026-124700: URL Redirection to Untrusted Site in Progress Telerik UI for WinForms

Status: published. Published: 2026-11-12. Updated: 2026-11-14.

In Telerik UI for WinForms, versions prior to 2026.4.1111, an untrusted URL redirection vulnerability exists that allows an attacker to launch arbitrary operating system protocol handlers with attacker-controlled arguments via crafted documents and hyperlinks with a non-allowlisted URI scheme that the user opens.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Progress Software / Telerik UI for WinForms: ≥ 2026.3.1007; < 2026.4.1111 (affected, custom). Source: CNA: ProgressSoftware

## Severity and prioritization

- CVSS 3.1: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H; source: CNA: ProgressSoftware

- CVSS 3.1: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H; source: NVD: security@progress.com

- CISA KEV: No listing in collected sources

- EPSS: 0.11% as of 2026-11-13; percentile 1.41%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-601

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://www.telerik.com/products/winforms/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124700 (CNA: ProgressSoftware; vendor-advisory)

- https://www.telerik.com/products/winforms/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124700 (security@progress.com)

## Provenance

- CNA: ProgressSoftware: https://www.cve.org/CVERecord?id=CVE-2026-124700; retrieved 2026-11-14; source updated 2026-11-14

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124700; retrieved 2026-11-13; source updated 2026-11-12

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-124700; retrieved 2026-11-14; source updated Not reported

Revision: 574bbbd63e6d60c9268b6665bfd4a0c272a7e8a9e15f993aa52b8a2d86d5c69c

Canonical: https://y2.dev/cve/CVE-2026-124700

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