I don't know if this is relevant to you users of JMRI? but Java is having security problems, and is under attack. My security Emsisoft has advised that users who don't need Java should consider uninstalling it. The flaw is in the latest Java and allows bypass of Java security sandbox.
It might have nothing to do with JMRI?
Railway42
It might have nothing to do with JMRI?
Railway42