Opera before 10.54 on Windows and Mac OS X, and before 10.60 on UNIX platforms, does not properly restrict certain uses of homograph characters in domain names, which makes it easier for remote attackers to spoof IDN domains via unspecified choices of characters.

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 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 9.52 and earlier allows remote attackers to cause a denial of service (unusable browser) by calling the window.print function in a loop, aka a "printing DoS attack," possibly a related issue to CVE-2009-0821.

Opera 9.52 and earlier allows remote attackers to cause a denial of service (CPU consumption) via a series of automatic submissions of a form containing a KEYGEN element, a related issue to CVE-2009-1828.

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 before 10.00 does not properly handle a (1) '\0' character or (2) invalid wildcard character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority.

Opera before 10.00 on Linux, Solaris, and FreeBSD does not properly implement the "INPUT TYPE=file" functionality, which allows remote attackers to trick a user into uploading an unintended file via vectors involving a "dropped file."