Information disclosure

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."...

Design/Logic Flaw

Opera before 9.52 does not properly restrict the ability of a framed web page to change the address associated with a different frame, which allows remote attackers to trigger the display of an arbitrary address in a frame via unspecified use of web script...