TYPO3's mail‑file spool deserialization flaw lets local users with write access to the spool directory craft a malicious file that is deserialized during the mailer:spool:send command, enabling arbitrary PHP code execution on the web server. This issue affects TYPO3 CMS versions 10.0.0-10.4.54, 11.0.0-11.5.48, 12.0.0-12.4.40, 13.0.0-13.4.22 and 14.0.0-14.0.1.

TYPO3 CMS Allows Insecure Deserialization via Mailer File Spool