The UI performs the wrong action in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network. The vulnerability, designated as CVE-2025-26643, is a high-level security risk that has the potential to allow unauthorized access to sensitive information and user data over the Internet. This long read post will provide a detailed analysis of the vulnerability, its impact, how it can be exploited, and what you can do to safeguard your IT infrastructure from it. Stay with us as we provide code snippets, links to original references, and important exploit details relevant to the CVE-2025-26643.

Understanding the Vulnerability

CVE-2025-26643 is a UI discrepancy in the chromium-based Microsoft Edge browser, which allows an attacker to spoof network data. The crux of the vulnerability lies in the fact that the wrong action is executed instead of the intended one, making it exceedingly simple for someone with malicious intent to intercept and manipulate network traffic. To better understand the issue, we will delve deeper into the specific code snippets where the vulnerability resides.

The following code snippet demonstrates the core issue in the Edge browser that enables spoofing

var getFakeLink = function() {
   var a = document.createElement("a");
   a.href = "https://www.example.com";;
   Object.defineProperty(a, "pathname", {
      get: function() {
         return "/exploit";
      }
   });
   return a;
};

var fakeLink = getFakeLink();
console.log(fakeLink.pathname); // Outputs "/exploit"
console.log(fakeLink.href);     // Outputs "https://www.example.com/exploit";

In the above code snippet, a fake link is created using JavaScript. The Object.defineProperty function is used to overwrite the "pathname" attribute of the link. While the console.log function successfully logs the spoofed input, the actual link still points to the original URL. Consequently, an authorized attacker is able to manipulate specific parts of a URL and disguise it as legitimate, potentially leading to devastating attacks such as phishing and data theft.

- Microsoft's Official Security Advisory on CVE-2025-26643
- National Vulnerability Database - CVE-2025-26643
- Chromium Project - Microsoft Edge

Exploit Details

The primary exploitation technique that attackers can leverage with CVE-2025-26643 is URL spoofing. By modifying the links on a webpage, cybercriminals can trick users into thinking they are clicking on legitimate links while actually being redirected to malicious websites. This can lead to users unknowingly exposing their personal information, such as login credentials, Social Security numbers, and credit card details, to the attacker. Frequent targets of such attacks include online banking services, e-commerce platforms, and social media websites, where sensitive information is abundant.

Preventing Attacks and Safeguarding Your Networks

While Microsoft has released patches and updates addressing the vulnerability in question, it is crucial to remain vigilant and implement proactive security measures. Here are a few steps that can help mitigate the risk of this vulnerability from being exploited:

1. Regularly update your software, such as operating systems, browsers, and antivirus programs, to ensure you are using the latest security patches.
2. Provide training to your employees regarding cybersecurity awareness and educate them about the dangers of phishing, malicious websites, and spoofed emails.
3. Promote the use of strong, unique passwords and consider implementing two-factor authentication, whenever possible, to protect against unauthorized access.
4. Conduct regular security audits of your IT infrastructure to identify potential weaknesses and vulnerabilities before they can be exploited by an attacker.

Conclusion

CVE-2025-26643 is a major security vulnerability in the chromium-based Microsoft Edge browser, which could lead to serious repercussions if exploited by an attacker. With the information presented in this long read post, including the code snippet, relevant references, and exploit details, you should now have a comprehensive understanding of the threat and how to protect your organization against it.

Remember, staying informed and vigilant is key to safeguarding your networks and data from cyberattacks. Stay safe and proactive in your approach to cybersecurity.

Timeline

Published on: 03/07/2025 19:15:37 UTC
Last modified on: 03/13/2025 17:34:08 UTC