CVE 2009-1105
The Java Plug-in in Java SE Development Kit (JDK) and Java Runtime Environment (JRE) 6 Update 12, 11, and 10 allows user-assisted remote attackers to cause a trusted applet to run in an older JRE version, which can be used to exploit vulnerabilities in that older version, aka CR 6706490.
See the 
CVE page on Mitre.org
for more details.
