BeanShell is a small, free, embeddable Java source interpreter with object scripting language features, written in Java.
An application that includes BeanShell on the classpath may be vulnerable if another part of the application uses Java serialization or XStream to deserialize data from an untrusted source.
Remote attackers could execute arbitrary code including shell commands.
There is no known workaround at this time.
All BeanShell users should upgrade to the latest version:
# emerge --sync
# emerge --ask --verbose --oneshot ">=dev-java/bsh-2.0_beta6"