You’ll have to change your password, but the company says your data is safe:
In our security investigation, we have found no evidence that any of the content you store in Evernote was accessed, changed or lost. We also have no evidence that any payment information for Evernote Premium or Evernote Business customers was accessed.
The investigation has shown, however, that the individual(s) responsible were able to gain access to Evernote user information, which includes usernames, email addresses associated with Evernote accounts and encrypted passwords. Even though this information was accessed, the passwords stored by Evernote are protected by one-way encryption. (In technical terms, they are hashed and salted.)
While our password encryption measures are robust, we are taking additional steps to ensure that your personal data remains secure. This means that, in an abundance of caution, we are requiring all users to reset their Evernote account passwords.
Evernote is being praised for its transparent response, forced password reset and that one-way encryption (LinkedIn, for example, didn’t have it when it was breached).