The CSPSource::schemeMatches function in WebKit/Source/core/frame/csp/CSPSource.cpp in the Content Security Policy (CSP) implementation in Blink, as used in Google Chrome before 48.0.2564.82, does not apply http policies to https URLs and does not apply ws policies to wss URLs, which makes it easier for remote attackers to determine whether a specific HSTS web site has been visited by reading a CSP report.
https://security.gentoo.org/glsa/201603-09
https://codereview.chromium.org/1455973003
https://code.google.com/p/chromium/issues/detail?id=544765
http://www.ubuntu.com/usn/USN-2877-1
http://www.securitytracker.com/id/1034801
http://www.securityfocus.com/bid/81430
http://www.debian.org/security/2016/dsa-3456
http://rhn.redhat.com/errata/RHSA-2016-0072.html
http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00046.html
http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00036.html
http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00035.html
http://googlechromereleases.blogspot.com/2016/01/stable-channel-update_20.html