XSS in Mailerpress – Email Marketing, Newsletter, Automation & Woocommerce Emails
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (34.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 34.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
Weakness classification (CWE)
References
- plugins.trac.wordpress.org/browser/mailerpress/tags/2.0.3/src/Actions/Shortcode…
- plugins.trac.wordpress.org/browser/mailerpress/tags/2.0.3/src/Api/Campaigns.php
- plugins.trac.wordpress.org/browser/mailerpress/tags/2.0.3/src/Api/Campaigns.php
- plugins.trac.wordpress.org/browser/mailerpress/tags/2.0.3/src/Api/Campaigns.php
- plugins.trac.wordpress.org/browser/mailerpress/tags/2.0.5/src/Api/Campaigns.php
- plugins.trac.wordpress.org/browser/mailerpress/tags/2.0.5/src/Api/Campaigns.php
- plugins.trac.wordpress.org/browser/mailerpress/trunk/src/Actions/Shortcodes/Cam…
- plugins.trac.wordpress.org/browser/mailerpress/trunk/src/Api/Campaigns.php
- plugins.trac.wordpress.org/browser/mailerpress/trunk/src/Api/Campaigns.php
- plugins.trac.wordpress.org/browser/mailerpress/trunk/src/Api/Campaigns.php
Frequently asked questions
- What is CVE-2026-8599?
- CVE-2026-8599 is a medium-severity vulnerability in Mailerpress – Email Marketing, Newsletter, Automation & Woocommerce Emails, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-06-09.
- How severe is CVE-2026-8599?
- Medium severity. CVSS v3 base score is 6.4 out of 10.