Well after the recent hallabaloo about MSIE having a remote code execution flaw in its XML parser I just recieved notice from McAffe that a similar flaw exists in Mozilla/FireFox.

And they patched it as fast as Microsoft did. Check you are up to date.

Mozilla Firefox Layout Engine Remote Code Execution Vulnerabilities [MTIS08-213-A]

Threat Identifier(s) CVE-2008-5500; CVE-2008-5501 Threat Type Vulnerability Risk Assessment Medium Main Threat Vectors Web; E-Mail User Interaction Required Yes Description Memory corruption vulnerabilities in Mozilla Firefox, Thunderbird, and SeaMonkey may lead to remote code execution. The flaws are specific to crashes in the layout engine within Firefox and other Mozilla products that share the same browser engine. Under certain circumstances, memory can become corrupted, leaving the application in an exploitable state. Importance Low. On December 16 Mozilla released a patch to address this issue.