Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App

The Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘event_type’ parameter in all versions up to, and including, 3.8.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The vulnerability is only exploitable when the Post SMTP Pro plugin is also installed and its Reporting and Tracking extension is enabled.

The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `handle_office365_oauth_redirect()` function in all versions up to, and including, 3.8.0. This is due to the function being hooked to `admin_init` without any `current_user_can()` check or nonce verification. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the site's Office 365 OAuth mail configuration (access token, refresh token, and user email) via a crafted URL. The configuration option is used during wizard setup of Microsoft365 SMTP, only available in the Pro option of the plugin. This could cause an Administrator to believe an attacker-controlled Azure app is their own, and lead them to connect the plugin to the attacker's account during configuration after upgrading to Pro.

The Post SMTP plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 3.6.1. This is due to the plugin not properly verifying that a user is authorized to update OAuth tokens on the 'handle_gmail_oauth_redirect' function. This makes it possible for authenticated attackers, with subscriber level access and above, to inject invalid or attacker-controlled OAuth credentials. CVE-2025-67563 appears to be a duplicate of this issue.

The Post SMTP – Complete SMTP Solution with Logs, Alerts, Backup SMTP & Mobile App plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the __construct function in all versions up to, and including, 3.6.0. This makes it possible for unauthenticated attackers to read arbitrary logged emails sent through the Post SMTP plugin, including password reset emails containing password reset links, which can lead to account takeover.

The Post SMTP – WP SMTP Plugin with Email Logs and Mobile App for Failure Notifications – Gmail SMTP, Office 365, Brevo, Mailgun, Amazon SES and more plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the 'update_post_smtp_pro_option_callback' function in all versions up to, and including, 3.4.1. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enable pro extensions.

The Post SMTP – WP SMTP Plugin with Email Logs and Mobile App for Failure Notifications – Gmail SMTP, Office 365, Brevo, Mailgun, Amazon SES and more plugin for WordPress is vulnerable privilege escalation via account takeover due to a missing capability check on the get_details() function in all versions up to, and including, 3.2.0. This makes it possible for authenticated attackers, with subscriber-level access and above, to access email logs which can contain password reset details and lead to an account takeover for any user, including administrators.

The Post SMTP plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the from and subject parameter in all versions up to, and including, 3.0.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Post SMTP plugin for WordPress is vulnerable to unauthorized access due to a missing capability check on the regenerate_qrcode() function in versions up to, and including, 2.9.11. This makes it possible for authenticated attackers, with subscriber-level access and above, to generate QR codes.