Sun SDK and Java Runtime Environment (JRE) 1.4.2 through 1.4.2_04, 1.4.1 through 1.4.1_07, and 1.4.0 through 1.4.0_04 allows untrusted applets and unprivileged servlets to gain privileges and read data from other applets via unspecified vectors related to classes in the XSLT processor, aka "XML sniffing."