Plaintext passwords are credentials stored or transmitted in a readable form rather than protected with an appropriate mechanism, such as secure password hashing for stored passwords or encryption for data in transit. Anyone who can access the exposed file, database, message, or backup may be able to read and use them.
In cyber security, plaintext credentials can turn a data exposure into an account-compromise risk. Attackers may try them on other services, especially when passwords are reused, or use them to access partner and internal systems. Defenders should avoid storing passwords in readable form, restrict access to credential stores, and use unique passwords with multi-factor authentication. If plaintext passwords may have been exposed, revoke or reset them promptly, investigate related accounts, and check for reuse. A report that passwords were included does not by itself prove they are genuine or usable; verify the claim while treating potential exposure seriously.