Anything within a sealed loop such as blood or brain fluid shouldn’t be boiling. Your body is pretty good at keeping that stuff inside as long as you don’t have any major cuts or something. That said, I don’t think even a minor cut suffered in the vacuum could clot or scab without oxygen.

All of the air in any of your orifices would rapidly get sucked out (including from one’s butt), and pretty much any liquids exposed to the resulting vacuum would boil. Negative pressure within the body means more room-temp boiling liquids, which then creates more air to get sucked out! It’s a feedback loop!

A space-exposed corpse would likely end up quite dehydrated for the above reason.