Opera is not vulnerable to the JPEG processing vulnerability in Microsoft’s GDI+ library.
Details:
Microsoft Security Bulletin MS04-028
Buffer Overrun in JPEG Processing (GDI+)
Vulnerable browser: MS Internet Explorer
Example image (crashes MSIE): http://sylvana.net/test/AP4.jpg
The Opera Web browser is not vulnerable to this exploit, because Opera uses another JPEG decoder, built into Opera itself. Opera does not use GDI+ for JPEG processing.
Malformed images using this exploit may display normallyin Opera, and will not cause crashes.