Which response header limits documents from loading from origins other than the source but would not mitigate XSS Inclusion attacks?

The Cross-Origin Embedder Policy (COEP) header is designed to control the behavior of embedded resources and documents that your site is allowed to load from different origins. Specifically, it limits which resources can be embedded in your site from external origins. By requiring that all cross-origin resources are marked with the appropriate headers, COEP helps to secure your application against certain cross-origin attacks and can contribute to a safer browsing experience.

However, COEP does not directly mitigate Cross-Site Scripting (XSS) attacks. XSS attacks exploit the user's trust in a particular site by executing malicious scripts from within that trusted environment. While COEP can enforce restrictions on the origin of external content, it does not address the root cause of XSS vulnerabilities, where scripts are injected into the same-origin content. As a result, COEP is relevant for managing the loading of external resources but does not inherently protect against the injection of malicious scripts.

Choosing COEP as the correct response highlights its role in managing resource loading policies while acknowledging its limitations regarding XSS attack mitigation. This understanding is crucial in the context of web security, as developers must implement additional strategies to prevent XSS attacks, such as input validation, output encoding, and implementing Content Security Policies (CSP