Unspecified vulnerability in Java Runtime Environment (JRE) for Sun JDK and JRE 6 Update 10 and earlier; JDK and JRE 5.0 Update 16 and earlier; and SDK and JRE 1.4.2_18 and earlier allows untrusted applets and applications to gain privileges via unknown vectors related to "deserializing calendar objects."

More... (http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2008-5353)