Opera before 11.00, when Opera Turbo is used, does not properly present information about problematic X.509 certificates on https web sites, which might make it easier for remote attackers to spoof trusted content via a crafted web site.

Opera before 10.63 does not prevent interpretation of a cross-origin document as a CSS stylesheet when the document lacks a CSS token sequence, which allows remote attackers to obtain sensitive information via a crafted document.

Opera before 10.63 does not properly restrict web script in unspecified circumstances involving reloads and redirects, which allows remote attackers to spoof the Address Bar, conduct cross-site scripting (XSS) attacks, and possibly execute arbitrary code by leveraging the ability of a script to interact with a web page from (1) a different domain or (2) a different security context.

Opera before 10.63 does not properly verify the origin of video content, which allows remote attackers to obtain sensitive information by using a video stream as HTML5 canvas content.

Opera before 10.63 does not ensure that the portion of a URL shown in the Address Bar contains the beginning of the URL, which allows remote attackers to spoof URLs by changing a window's size.

Opera before 10.63 does not properly select the security context of JavaScript code associated with an error page, which allows user-assisted remote attackers to conduct cross-site scripting (XSS) attacks via a crafted web site.

Opera before 10.63 allows user-assisted remote web servers to cause a denial of service (application crash) by sending a redirect during the saving of a file.

Opera before 10.63 allows remote attackers to cause a denial of service (application crash) via a Flash movie with a transparent Window Mode (aka wmode) property, which is not properly handled during navigation away from the containing HTML document.

Opera before 10.63 allows remote attackers to cause a denial of service (memory corruption) by referencing an SVG document in an IMG element.

Opera before 10.61 does not properly suppress clicks on download dialogs that became visible after a recent tab change, which allows remote attackers to conduct clickjacking attacks, and consequently execute arbitrary code, via vectors involving (1) closing a tab or (2) hiding a tab, a related issue to CVE-2005-2407.