As of 8.0.32, WebappClassLoaderBase.filter() now looks for "org" in the class name, but if the class name happens to be just "org", it throws a StringIndexOutOfBoundsException at line 2780. This may seem minor (who's got a class called "org"?) but it's not, because applications that use Rhino will hit this problem very quickly. When loading a class a.b.c.MyClass, Rhino will try to load each package, i.e. a, then a.b, then a.b.c, then finally a.b.c.MyClass. So if you try to load a class that's in a org package, you get the exception. The fix should be simple: if the class name starts with "org", do *not* assume that it's longer than 3 characters.
*** This bug has been marked as a duplicate of bug 58999 ***