Your subject line is kind of inaccurate. Somebody might have obtained a few LastPass encrypted “blobs” (what a few of the LastPass guys call it), with which they might be able to decrypt accounts with very weak master passwords.
I have a long complicated master password, so I’m not worried. If you were dumb enough to secure all your passwords with a simple dictionary word…lol.
Last Pass has been forthright in disclosure. If they are correct about the mass of data possibly compromised it appears likely the risk is small. The stronger your LastPass password the smaller the chances of any harm at all even in the worst case. If you are using “password” as your master password… If you are using a long random string on a yubikey you are pretty safe!
I’ll be curious what the real security gurus have to say.