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 6.0 and earlier allows remote attackers to access sensitive information such as cookies and links for other domains via Javascript that uses setTimeout to (1) access data after a new window to the domain has been opened or (2) access data via about:cache.

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.

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.