SSRF in Mailgun For WordPress
CVE-2026-78003
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-78003?
- CVE-2026-78003 is a critical-severity vulnerability in Mailgun For WordPress, classified under Server-Side Request Forgery (SSRF). CVSS score: 9.8/10. Published 2026-08-22.
- How severe is CVE-2026-78003?
- Critical severity. CVSS v3 base score is 9.8 out of 10.