CVE 2008-4066
Mozilla Firefox 2.0.0.14, and other versions before 2.0.0.17, allows remote attackers to bypass cross-site scripting (XSS) protection mechanisms and conduct XSS attacks via HTML-escaped low surrogate characters that are ignored by the HTML parser, as demonstrated by a "jav�ascript" sequence, aka "HTML escaped low surrogates bug."
See the 
CVE page on Mitre.org
for more details.
