The Salon Booking System WordPress plugin before 10.31.9 does not generate its booking-API access tokens from a secure random source, instead deriving them from a value hardcoded in the Salon Booking System WordPress plugin before 10.31.9 and the second at which a token was issued. An attacker able to constrain when a staff or administrator token was issued can compute a valid token and access the booking API as that user, including an administrator.