Opera before 10.50 on Windows, before 10.52 on Mac OS X, and before 10.60 on UNIX platforms makes widget properties accessible to third-party domains, which allows remote attackers to obtain potentially sensitive information via a crafted web site.

Opera before 10.60 does not properly restrict certain interaction between plug-ins, file inputs, and the clipboard, which allows user-assisted remote attackers to trigger the uploading of arbitrary files via a crafted web site.

Opera does not properly manage the address bar between the request to open a URL and the retrieval of the new document's content, which might allow remote attackers to conduct spoofing attacks via a crafted HTML document, a related issue to CVE-2010-1206.

Multiple unspecified vulnerabilities in Opera before 10.54 have unknown impact and attack vectors related to (1) "extremely severe," (2) "highly severe," (3) "moderately severe," and (4) "less severe" issues.

Opera before 10.53 on Windows and Mac OS X does not properly handle a series of document modifications that occur asynchronously, which allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via JavaScript that writes <marquee> sequences in an infinite loop, leading to attempted use of uninitialized memory. NOTE: this might overlap CVE-2006-6955.

Opera before 10.01 does not properly restrict HTML in a (1) RSS or (2) Atom feed, which allows remote attackers to conduct cross-site scripting (XSS) attacks, and conduct cross-zone scripting attacks involving the Feed Subscription Page to read feeds or create feed subscriptions, via a crafted feed, related to the rendering of the application/rss+xml content type as "scripted content."

Opera allows remote attackers to cause a denial of service (application crash) via a web page that contains a large number of nested marquee tags, a related issue to CVE-2006-2723.