Opera 9.52 and earlier, and 10.00 Beta 3 Build 1699, does not properly block data: URIs in Location headers in HTTP responses, which allows remote attackers to conduct cross-site scripting (XSS) attacks via vectors related to (1) injecting a Location header that contains JavaScript sequences in a data:text/html URI or (2) entering a data:text/html URI with JavaScript sequences when specifying the content of a Location header. NOTE: the JavaScript executes outside of the context of the HTTP site.

Opera 9.52 and earlier allows remote attackers to cause a denial of service (CPU and memory consumption, and application hang) via a long Unicode string argument to the write method, a related issue to CVE-2009-2479.

Opera, possibly 9.64 and earlier, allows remote attackers to cause a denial of service (memory consumption) via a large integer value for the length property of a Select object, a related issue to CVE-2009-1692.

Opera 9.52 and earlier does not block javascript: URIs in Refresh headers in HTTP responses, which allows remote attackers to conduct cross-site scripting (XSS) attacks via vectors related to (1) injecting a Refresh header or (2) specifying the content of a Refresh header, a related issue to CVE-2009-1312. NOTE: it was later reported that 10.00 Beta 3 Build 1699 is also affected.

Opera detects http content in https web pages only when the top-level frame uses https, which allows man-in-the-middle attackers to execute arbitrary web script, in an https site's context, by modifying an http page to include an https iframe that references a script file on an http site, related to "HTTP-Intended-but-HTTPS-Loadable (HPIHSL) pages."

Opera, possibly before 9.25, processes a 3xx HTTP CONNECT response before a successful SSL handshake, which allows man-in-the-middle attackers to execute arbitrary web script, in an https site's context, by modifying this CONNECT response to specify a 302 redirect to an arbitrary https web site.

Opera, possibly before 9.25, uses the HTTP Host header to determine the context of a document provided in a (1) 4xx or (2) 5xx CONNECT response from a proxy server, which allows man-in-the-middle attackers to execute arbitrary web script by modifying this CONNECT response, aka an "SSL tampering" attack.

Opera executes DOM calls in response to a javascript: URI in the target attribute of a submit element within a form contained in an inline PDF file, which might allow remote attackers to bypass intended Adobe Acrobat JavaScript restrictions on accessing the document object, as demonstrated by a web site that permits PDF uploads by untrusted users, and therefore has a shared document.domain between the web site and this javascript: URI. NOTE: the researcher reports that Adobe's position is "a PDF file is active content."

Unspecified vulnerability in Opera before 9.64 has unknown impact and attack vectors, related to a "moderately severe issue."

Opera before 9.64 allows remote attackers to conduct cross-domain scripting attacks via unspecified vectors related to plug-ins.

Opera before 9.64 allows remote attackers to execute arbitrary code via a crafted JPEG image that triggers memory corruption.

Unspecified vulnerability in Opera before 9.63 allows remote attackers to "reveal random data" via unknown vectors.

Cross-site scripting (XSS) vulnerability in Opera before 9.63 allows remote attackers to inject arbitrary web script or HTML via built-in XSLT templates.

Opera before 9.63 does not block unspecified "scripted URLs" during the feed preview, which allows remote attackers to read existing subscriptions and force subscriptions to arbitrary feed URLs.

Multiple buffer overflows in Opera before 9.63 might allow (1) remote attackers to execute arbitrary code via a crafted text area, or allow (2) user-assisted remote attackers to execute arbitrary code via a long host name in a file: URL. NOTE: this might overlap CVE-2008-5178.

Opera before 9.61 does not properly block scripts during preview of a news feed, which allows remote attackers to create arbitrary new feed subscriptions and read the contents of arbitrary feeds.

The Fast Forward feature in Opera before 9.61, when a page is located in a frame, executes a javascript: URL in the context of the outermost page instead of the page that contains this URL, which allows remote attackers to conduct cross-site scripting (XSS) attacks.

Opera before 9.52 does not check the CRL override upon encountering a certificate that lacks a CRL, which has unknown impact and attack vectors. NOTE: it is not clear whether this is a vulnerability, but the vendor included it in a security section of the advisory.

Opera before 9.52 does not ensure that the address field of a news feed represents the feed's actual URL, which allows remote attackers to change this field to display the URL of a page containing web script controlled by the attacker.

Opera before 9.52 does not prevent use of links from web pages to feed source files on the local disk, which might allow remote attackers to determine the validity of local filenames via vectors involving "detection of JavaScript events and appropriate manipulation."