Sun has released new versions of both JDK and JRE that contain fixes for multiple security vulnerabilities. However, ebuild's of these new versions (1.6.0.05, 1.5.0.15) are still missing from portage. Only the 1.4-series has been updated in portage (version 1.4.0.17) so far. Release notes: http://java.sun.com/javase/6/webnotes/ReleaseNotes.html
us-cert announcement (2008-03-06): http://www.us-cert.gov/cas/techalerts/TA08-066A.html
*** This bug has been marked as a duplicate of bug 212425 ***