Severity: Critical
CVSS Score: 9.3
nsHTMLContentSink.cpp in Mozilla Firefox and Thunderbird 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unknown vectors involving a "particular sequence of HTML tags" that leads to memory corruption.