The child frames in Opera 9 before 9.20 inherit the default charset from the parent window when a charset is not specified in an HTTP Content-Type header or META tag, which allows remote attackers to conduct cross-site scripting (XSS) attacks, as demonstrated using the UTF-7 character set.
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.
Heap-based buffer overflow in Opera 9.02 allows remote attackers to execute arbitrary code via a JPEG file with an invalid number of index bytes in the Define Huffman Table (DHT) marker.
The Javascript SVG support in Opera before 9.10 does not properly validate object types in a createSVGTransformFromMatrix request, which allows remote attackers to execute arbitrary code via JavaScript code that uses an invalid object in this request that causes a controlled pointer to be referenced during the virtual function call.