AES256 is still secure, assuming the encryption key has ~256 bits of entropy (32 random bytes). Assuming your master password is reasonably complex, hopefully the encryption key derived from your password has enough entropy.
Despite this, I recommend rotating all passwords (if you don't have the time, prioritize rotating passwords on important accounts / putting MFA on them). For all we know, lastpass might have had a full compromise (i.e. access to unencrypted vaults from malicious source code commits).
Despite this, I recommend rotating all passwords (if you don't have the time, prioritize rotating passwords on important accounts / putting MFA on them). For all we know, lastpass might have had a full compromise (i.e. access to unencrypted vaults from malicious source code commits).