Language names in Accept-Language header are now always canonicalized

Published: | Categories: Networking, Privacy & Security


Previously, language names in the HTTP Accept-Language request header turned out to be lowercase, like en-US to en-us, when the user had changed their preferred language through the browser’s Preferences page. This issue has been fixed with Firefox 36, not only because those names were not canonicalized, but because that behaviour increased the fingerprintability of the browser.