Opera before 12.00 Beta allows remote attackers to cause a denial of service (application crash) via crafted WebGL content, as demonstrated by a codeflow.org WebGL demo.

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.

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 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 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 11.65 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 11.64 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 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 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.