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This security vulnerability affects Microsoft .NET projects utilizing the Microsoft.WindowsDesktop.App.Runtime package, specifically impacting WPF applications through multiple weaknesses in XAML and XPS file parsing. Attackers can exploit these flaws by supplying maliciously crafted files or hyperlinks containing unsafe URI fetching vectors, deep nesting structures, or untrusted input states. When an unsuspecting user navigates or opens these files, the runtime fails to adequately isolate or restrict navigational privileges, leading to unsafe resource loading and potential code execution. Furthermore, vulnerabilities involving improper handling of TrueType fonts and DNS zone-policy caching enable attackers to bypass defense mechanisms. Mitigation requires installing updated runtime packages, recompiling self-contained deployments, and restarting affected applications to secure the parsing pipeline.
DailyCVE Form:
Platform: Windows .NET WPF
Version: 8.0 to 11.0
Vulnerability : Deserialization Remote Code
Severity: High
date: 2026-10-13
Prediction: 2026-10-13
What Undercode Say
The vulnerability stems from improper handling and parsing mechanisms within restrictive XAML and XPS implementations in the .NET desktop runtime. Developers must carefully audit user-supplied markup content and ensure strict validation is enforced on all URI navigations and font resources. Utilizing outdated runtime packages leaves applications completely exposed to remote attacks if users interact with malicious files or links.
dotnet --info dotnet add package Microsoft.WindowsDesktop.App.Runtime --version 10.0.13 dotnet publish -c Release --self-contained true
// Example conceptual code check for runtime version verification
using System;
class Program
{
static void Main()
{
Console.WriteLine(".NET Desktop Runtime Security Check initialized.");
}
}
Exploit: (Educational Purposes!)
An attacker constructs a malicious XAML payload containing deep nesting structures and unsafe URI navigation schemes designed to trick the parser into fetching external resources or executing unauthorized payloads. When the victim opens the crafted document or clicks a malicious hyperlink within an affected WPF application, untrusted input states propagate through the navigation stack, bypassing standard security restrictions and triggering code execution under the context of the current user.
Protection: from this CVE
To protect your applications against this vulnerability, you must immediately update your .NET SDK and runtime packages to the latest patched versions (such as 8.0.32, 9.0.21, 10.0.13, or 11.0.0-rc.2). If you have deployed self-contained applications targeting any of the impacted versions, you must recompile and redeploy those applications after applying the updates. Always ensure that user-supplied XAML and XPS inputs are strictly sanitized and validated before rendering.
Impact:
Successful exploitation of this vulnerability can allow a remote attacker to execute arbitrary code on the victim’s machine under the current user privileges. This can result in complete compromise of confidentiality, integrity, and availability of the affected application and its underlying system resources, depending on the permissions granted to the running user process.
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Sources:
Reported By: github.com
Extra Source Hub:
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