Description

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.1",
  "pubDate": "2026-09-11T20:18:45.403Z",
  "pubdate": "2026-09-11T20:18:45.403Z",
  "executiveSummary": "This vulnerability involves an Improper Neutralization of Input During Web Page Generation, classified as a Cross-Site Scripting (XSS) flaw within the Chromium-based Microsoft Edge browser.\nThe vulnerability allows a remote, unauthorized attacker to execute malicious scripts within the context of the user's browser session, facilitating spoofing attacks over a network.\nImpact includes potential unauthorized modification of displayed content, session hijacking, or the execution of arbitrary actions on behalf of the authenticated user.\nThe risk is critical for users interacting with untrusted or maliciously crafted web content, as the browser fails to correctly sanitize inputs that subsequently influence the rendering of web pages.\nSuccessful exploitation requires the attacker to entice a user to navigate to a specifically crafted URI or interact with compromised web resources, leveraging the browser's trust in rendered output to deceive the victim.",
  "technicalDetails": "The root cause of this vulnerability lies in the improper sanitization and neutralization of user-controlled input before it is processed by the web page rendering engine in Microsoft Edge (Chromium-based). By failing to adequately escape or validate data streams, the browser permits the injection of malicious script payloads into the Document Object Model (DOM).\nThe vulnerability manifests when the application renders content that includes malicious scripts as if it were legitimate, trusted data. In a typical attack flow, the attacker identifies a vector—such as a URL parameter, a form field, or a vulnerable UI element—that reflects input directly into the page's HTML context. When the user interacts with this vector, the injected script executes within the security origin of the site.\nThe exploit allows the execution of arbitrary JavaScript, granting the attacker the ability to manipulate the Document Object Model to perform spoofing. This could involve modifying the visual elements of a legitimate page to deceive the user, such as altering credentials fields, displaying fake alerts, or injecting unauthorized links. Because the script executes in the user's current session, it may bypass certain same-origin policy protections if the injection occurs on a target domain with elevated privileges.\nFrom a networking perspective, this attack is executable over a network via standard HTTP/HTTPS channels. There is no requirement for prior authentication; the exploit is triggered solely through the browser's rendering process. The payload behavior involves the browser interpreting the injected script tags or event handlers (e.g., onload or onerror) as part of the intended page structure, rather than as literal string data.\nPost-exploitation, the impact is significant, ranging from the theft of session tokens (if HttpOnly flags are absent on cookies) to cross-site request forgery (CSRF) or the silent redirection of users to malicious phishing infrastructure. The browser's inability to distinguish between intended application code and injected malicious data compromises the entire trust model of the client-side execution environment."
}