Toshiba printers use Sendmail to send emails to recipients. Sendmail is used with several insecure directories. A local attacker can inject a malicious Sendmail configuration file. As for the affected products/models/versions, see the reference URL.
https://www.toshibatec.com/information/pdf/information20240531_01.pdf
https://www.toshibatec.com/information/20240531_01.html