Opera allows remote attackers to cause a denial of service (invalid memory reference and application crash) via a web page or HTML email that contains a TBODY tag with a large COL SPAN value, as demonstrated by mangleme.

Opera 7.50 and earlier allows remote web sites to provide a "Shortcut Icon" (favicon) that is wider than expected, which could allow the web sites to spoof a trusted domain and facilitate phishing attacks using a wide icon and extra spaces.

Argument injection vulnerability in Opera before 7.50 does not properly filter "-" characters that begin a hostname in a telnet URI, which allows remote attackers to insert options to the resulting command line and overwrite arbitrary files via (1) the "-f" option on Windows XP or (2) the "-n" option on Linux.

Opera allows remote attackers to bypass intended cookie access restrictions on a web application via "%2e%2e" (encoded dot dot) directory traversal sequences in a URL, which causes Opera to send the cookie outside the specified URL subsets, e.g. to a vulnerable application that runs on the same server as the target application.