content/browser/web_contents/web_contents_impl.cc in Google Chrome before 44.0.2403.89 does not ensure that a PDF document's modal dialog is closed upon navigation to an interstitial page, which allows remote attackers to spoof URLs via a crafted document, as demonstrated by the alert_dialog.pdf document.
https://security.gentoo.org/glsa/201603-09
https://codereview.chromium.org/1156663004/
https://codereview.chromium.org/1150843002/
https://code.google.com/p/chromium/issues/detail?id=482380
http://www.securitytracker.com/id/1033031
http://www.securityfocus.com/bid/75973
http://www.debian.org/security/2015/dsa-3315
http://rhn.redhat.com/errata/RHSA-2015-1499.html
http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00038.html
http://googlechromereleases.blogspot.com/2015/07/stable-channel-update_21.html