In Midori Browser 0.5.11 (on Windows 10), Content Security Policy (CSP) is not applied correctly to all parts of multipart content sent with the multipart/x-mixed-replace MIME type. This could result in script running where CSP should have blocked it, allowing for cross-site scripting (XSS) and other attacks when the product renders the content as HTML. Remediating this would also need to consider the polyglot case, e.g., a file that is a valid GIF image and also valid JavaScript.