Why is my account locked for security reasons
If you see a message that says your account has been locked, it’s usually a result of someone trying to log in with your Yahoo! ID and an incorrect password one too many times.
As a security measure, your account has been locked to prevent unauthorized users from being able to log in to it. If you have not recently tried to log in, this is not necessarily a cause for concern. Another Yahoo! user may have mistakenly used your ID when attempting to log in.
The lock on your account will expire 24 hours after it was first locked. Don’t worry—the lockout time period won’t reset each time you try to sign in while the account is still locked. You can try to sign in again after the lockout time has expired. Note: Yahoo! is unable to provide you with the exact time that your account was locked or when it will be unlocked.
If you are still unable to sign in with your new password, please see the password problems help page for some common reasons why you are seeing the "Invalid Password" error.
To learn more about account security, please visit the Yahoo! Security Center.