Opera before 11.00 does not properly handle security policies during updates to extensions, which might allow remote attackers to bypass intended access restrictions via unspecified vectors.

The default configuration of Opera before 11.00 enables WebSockets functionality, which has unspecified impact and remote attack vectors, possibly a related issue to CVE-2010-4508.

Opera before 11.00 does not properly constrain dialogs to appear on top of rendered documents, which makes it easier for remote attackers to trick users into interacting with a crafted web site that spoofs the (1) security information dialog or (2) download dialog.

Unspecified vulnerability in Opera before 11.00 has unknown impact and attack vectors, related to "a high severity issue."

Opera before 11.00 on Windows does not properly implement the Insecure Third Party Module warning message, which might make it easier for user-assisted remote attackers to have an unspecified impact via a crafted module.

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.