WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp in Blink, as used in Google Chrome before 52.0.2743.82, does not consider referrer-policy information inside an HTML document during a preload request, which allows remote attackers to bypass the Content Security Policy (CSP) protection mechanism via a crafted web site, as demonstrated by a "Content-Security-Policy: referrer origin-when-cross-origin" header that overrides a "<META name='referrer' content='no-referrer'>" element.