I've discovered similar issues in TLS implementations, but I don't think this is actually a vulnerability without more details. Just because a client will use b

I've discovered similar issues in TLS implementations, but I don't think this is actually a vulnerability without more details. Just because a client will use bad parameters doesn't mean that it will use its existing key with those bad parameters. It shouldn't be hard to make a PoC if this is in fact what is going on.