PHPMailer 6.4.1 and earlier contain a vulnerability that can result in untrusted code being called (if such code is injected into the host project's scope by other means). If the $patternselect parameter to validateAddress() is set to 'php' (the default, defined by PHPMailer::$validator), and the global namespace contains a function called php, it will be called in preference to the built-in validator of the same name. Mitigated in PHPMailer 6.5.0 by denying the use of simple strings as validator function names.

PHPMailer before 6.5.0 on Windows allows remote code execution if lang_path is untrusted data and has a UNC pathname.

Low privileged users can use the AJAX action 'cp_plugins_do_button_job_later_callback' in the WooCommerce Conditional Marketing Mailer WordPress plugin before 1.5.2, to install any plugin (including a specific version) from the WordPress repository, as well as activate arbitrary plugin from then blog, which helps attackers install vulnerable plugins and could lead to more critical vulnerabilities like RCE.

PHPMailer 6.1.8 through 6.4.0 allows object injection through Phar Deserialization via addAttachment with a UNC pathname. NOTE: this is similar to CVE-2018-19296, but arose because 6.1.8 fixed a functionality problem in which UNC pathnames were always considered unreadable by PHPMailer, even in safe contexts. As an unintended side effect, this fix eliminated the code that blocked addAttachment exploitation.

Privilege chaining vulnerability in acmailer ver. 4.0.2 and earlier, and acmailer DB ver. 1.1.4 and earlier allows remote attackers to bypass authentication and to gain an administrative privilege which may result in obtaining the sensitive information on the server via unspecified vectors.

Improper access control vulnerability in acmailer ver. 4.0.1 and earlier, and acmailer DB ver. 1.1.3 and earlier allows remote attackers to execute an arbitrary OS command, or gain an administrative privilege which may result in obtaining the sensitive information on the server via unspecified vectors.

This affects the package nodemailer before 6.4.16. Use of crafted recipient email addresses may result in arbitrary command flag injection in sendmail transport for sending mails.

Jenkins Mailer Plugin 1.32 and earlier does not perform hostname validation when connecting to the configured SMTP server.

SuperWebMailer 7.21.0.01526 is susceptible to a remote code execution vulnerability in the Language parameter of mailingupgrade.php. An unauthenticated remote attacker can exploit this behavior to execute arbitrary PHP code via Code Injection.

PHPMailer before 6.1.6 contains an output escaping bug when the name of a file attachment contains a double quote character. This can result in the file type being misinterpreted by the receiver or any mail relay processing the message.