That's not how it works. You're not privy to the internal operations of Yahoo simply because you own stock. And as regards your role as a security researcher, t

That's not how it works. You're not privy to the internal operations of Yahoo simply because you own stock. And as regards your role as a security researcher, they're not obligated to disclose logs or, indeed, provide you any detail whatsoever about their security response. They say they've contained the problem, you (presumably) can't still perform the exploit, end of story, unless you have evidence that more servers were compromised than Stamos admits.