CVE-2026-78003: Mailgun For WordPress

Critical severity, CVSS 9.8. EPSS: 0.8% chance of exploitation in the next 30 days.

The Mailgun for WordPress plugin for WordPress is vulnerable to Server-Side Request Forgery (SSRF) via path traversal in versions up to and including 2.2.0. This is due to insufficient input validation in the add_list() function, which accepts user-controlled array keys from $_POST['addresses'], passes them through sanitize_text_field(). This makes it possible for unauthenticated attackers to make authenticated POST requests to any Mailgun API endpoint using the WordPress site's API key, including creating inbound email-forwarding routes that can intercept password reset emails, leading to administrator account takeover.

Affected products

• Mailgun Mailgun For WordPress: up to and including 2.2.0

Published 2026-08-22. Last modified 2026-08-25.