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.