Opera 7.x and 8 before 8.01 does not clearly associate a Javascript dialog box with the web page that generated it, which allows remote attackers to spoof a dialog box from a trusted site and facilitates phishing attacks, aka the "Dialog Origin Spoofing Vulnerability."

The XMLHttpRequest object in Opera 8.0 Final Build 1095 allows remote attackers to bypass access restrictions and perform unauthorized actions on other domains via a redirect.

Cross-site scripting (XSS) vulnerability in Opera 8.0 Final Build 1095 allows remote attackers to inject arbitrary web script or HTML via "javascript:" URLs when a new window or frame is opened, which allows remote attackers to bypass access restrictions and perform unauthorized actions on other domains.

The International Domain Name (IDN) support in Opera 7.54 allows remote attackers to spoof domain names using punycode encoded domain names that are decoded in URLs and SSL certificates in a way that uses homograph characters from other character sets, which facilitates phishing attacks.

Opera 7.54 and earlier on Gentoo Linux uses an insecure path for plugins, which could allow local users to gain privileges by inserting malicious libraries into the PORTAGE_TMPDIR (portage) temporary directory.

The International Domain Name (IDN) support in Epiphany allows remote attackers to spoof domain names using punycode encoded domain names that are decoded in URLs and SSL certificates in a way that uses homograph characters from other character sets, which facilitates phishing attacks.

Opera 8 Beta 3, when using first-generation vetted digital certificates, displays the Organizational information of an SSL certificate, which is easily spoofed and can facilitate phishing attacks.

The International Domain Name (IDN) support in Firefox 1.0, Camino .8.5, and Mozilla before 1.7.6 allows remote attackers to spoof domain names using punycode encoded domain names that are decoded in URLs and SSL certificates in a way that uses homograph characters from other character sets, which facilitates phishing attacks.

Opera 7.54 and earlier does not properly validate base64 encoded binary data in a data: (RFC 2397) URL, which causes the URL to be obscured in a download dialog, which may allow remote attackers to trick users into executing arbitrary code.

Opera 7.54 allows remote attackers to cause a denial of service (application crash from memory exhaustion), as demonstrated using Javascript code that continuously creates nested arrays and then sorts the newly created arrays.