The CPU isn't listed by name, but the top speed is listed at 2.15GHz. We also know that this tablet is running on some version of Android 4.2.2, though of course Amazon will likely have customized it to suit their own purposes.
Today's "leak" ties in with a 2 week old leak which said that the new KFHD 8.9 would be powered by a quad-core Qualcomm Snapdragon 800 and run Android 4.2.2:
The larger 8.9-inch Kindle Fire HD model Amazon is planning to release this fall features specs similar to the 7-inch model behind its 2,560 x 1,600-pixel high-definition display. Sources state that the same Qualcomm Snapdragon 800 chipset will power the tablet and it will also feature the same front-facing camera, optional cellular data support, internal storage sizes and 2GB of RAM. The 8.9-inch model will also feature an 8-megapixel rear camera though, while the 7-inch model will not include a rear camera.
The benchmarks don't include details on the other specs, but I would not be surprised if they were accurate. That earlier leak came from Boy Genius Report, and based on their past accuracy I would suggest that BGR is one of Amazon's preferred venues for leaks (how I envy them).
There's also no news on when Amazon plans to unveil the new tablet, but I am guessing that Amazon's launch will happen right before Kobo's event on 27 August. If nothing else it would be a good way to upstage Kobo.