CVE-2026-8599: The MailerPress – Email Marketing, Newsletter, Email Automation & WooCommerce Emails plugin for WordPress is vulnerable to Stored Cross-Site Scripting...

Description

The MailerPress – Email Marketing, Newsletter, Email Automation & WooCommerce Emails plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Campaign HTML Content Field in all versions up to, and including, 2.0.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The public-facing campaign preview endpoint (/mp-email/{id}-slug/) is not affected by this vulnerability, as it applies a Content-Security-Policy header blocking all inline scripts; exploitation is limited to the admin dashboard preview.

Metrics

CVSS 3.1

6.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

EPSS Probability

0.23%

14.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Jun 9, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-8599?

The MailerPress – Email Marketing, Newsletter, Email Automation & WooCommerce Emails plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Campaign HTML Content Field in all versions up to, and including, 2.0.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The public-facing campaign preview endpoint (/mp-email/{id}-slug/) is not affected by this vulnerability, as it applies a Content-Security-Policy header blocking all inline scripts; exploitation is limited to the admin dashboard preview.

How severe is CVE-2026-8599?

CVE-2026-8599 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2026-8599?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.