Buffer overflow in Opera 6.01 allows remote attackers to cause a denial of service (crash) via an IMG tag with large width and height attributes.
Opera 5.11 allows remote attackers to cause a denial of service (CPU consumption and memory leak) via a web page with a large number of images.
Opera 5.0 for Linux does not properly handle malformed HTTP headers, which allows remote attackers to cause a denial of service, possibly with a header whose value is the same as a MIME header name.