Opera before 12.00 Beta allows user-assisted remote attackers to cause a denial of service (application hang) via JavaScript code that changes a form before submission.

Opera before 12.00 Beta allows remote attackers to cause a denial of service (application crash) via crafted characters in domain names, as demonstrated by "IDNA2008 tests."

Opera before 12.00 Beta allows remote attackers to cause a denial of service (application hang) via an absolutely positioned wrap=off TEXTAREA element located next to an "overflow: auto" block element.

Opera before 12.00 Beta allows remote attackers to cause a denial of service (application crash) via a web page that contains invalid character encodings.

Opera before 12.00 Beta allows user-assisted remote attackers to cause a denial of service (application crash) via a crafted web page that is not properly handled during a reload, as demonstrated by a "multiple origin camera test" page.

Opera before 11.64 does not properly allocate memory for URL strings, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted string.

Opera before 11.65 does not ensure that the address field corresponds to the displayed web page during blocked navigation, which makes it easier for remote attackers to conduct spoofing attacks by detecting and preventing attempts to load a different web page.

Unspecified vulnerability in Opera before 12.00 on Mac OS X has unknown impact and attack vectors, related to a "moderate severity issue."

Opera before 11.65 does not ensure that the address field corresponds to the displayed web page during unusually timed changes to this field, which makes it easier for user-assisted remote attackers to conduct spoofing attacks via vectors involving navigation, reloads, and redirects.

Opera before 11.65 does not properly restrict the reading of JSON strings, which allows remote attackers to perform cross-domain loading of JSON resources and consequently obtain sensitive information via a crafted web site.

Opera before 11.65 does not properly restrict the opening of a pop-up window in response to the first click of a double-click action, which makes it easier for user-assisted remote attackers to conduct cross-site scripting (XSS) attacks or execute arbitrary code via a crafted web site.

Opera before 11.65 does not ensure that keyboard sequences are associated with a visible window, which makes it easier for user-assisted remote attackers to conduct cross-site scripting (XSS) attacks or execute arbitrary code via a crafted web site, related to a "hidden keyboard navigation" issue.

Opera before 9.63 does not properly verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

Opera before 11.62 on UNIX, when used in conjunction with an unspecified printing application, allows local users to overwrite arbitrary files via a symlink attack on a temporary file during printing.

Opera before 11.62 on UNIX uses world-readable permissions for temporary files during printing, which allows local users to obtain sensitive information by reading these files.

Opera before 11.62 on Mac OS X allows remote attackers to spoof the address field and security dialogs via crafted styling that causes page content to be displayed outside of the intended content area.

Opera before 11.62 allows remote attackers to spoof the address field by triggering a page reload followed by a redirect to a different domain.

Opera before 11.62 allows remote attackers to spoof the address field by triggering the launch of a dialog window associated with a different domain.

Opera before 11.62 allows remote attackers to bypass the Same Origin Policy via the (1) history.pushState and (2) history.replaceState functions in conjunction with cross-domain frames, leading to unintended read access to history.state information.

Opera before 11.62 does not ensure that a dialog window is placed on top of content windows, which makes it easier for user-assisted remote attackers to trick users into downloading and executing arbitrary files via a download dialog located under other windows.