Opera 3.2.1 allows remote attackers to cause a denial of service (application crash) via a URL that contains an extra / in the http:// tag.
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.
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.