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 accepts UTF-8 encodings that are not the "shortest" form, which makes it easier for attackers to bypass protection mechanisms for other applications that rely on shortest-form UTF-8 encodings.