The number of failed login attempts due to a wrong password has increased abnormally.
The authentication metrics suggests that bots are trying to brute-force passwords. Several contributors receive the following notification: "There has been a failed attempt to log in to your account from a new device. Please make sure your account has a strong password".
Public version of private dupe T193762
Longer explanation for community members below - also on Wikimedia-l
Sysops and other users with advanced user rights can enable two-factor authentication.