CVE-2026-8599

MailerPress <= 2.0.4 - Authenticated (Author+) Stored Cross-Site Scripting via Campaign HTML Content Field

2026-06-08 19:47
Faizan Shaik

Strategic Overview

Status
Patched in 2.0.5
Affected Plugin
MailerPress – Email Marketing, Newsletter, Email Automation & WooCommerce Emails
Affected Version
<= 2.0.4
CVSS
6.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-8599
View all MailerPress – Email Marketing, Newsletter, Email Automation & WooCommerce Emails vulnerabilities

At a glance

CVE-2026-8599 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the MailerPress WordPress plugin, affecting versions <= 2.0.4. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Author level or above. The issue is fixed in version 2.0.5; sites on affected versions should update now. Disclosed June 2026, reported by Faizan Shaik.

Vulnerability Overview

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.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in MailerPress <= 2.0.4 takes an account at Author level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For MailerPress the fix is 2.0.5: builds <= 2.0.4 are affected, anything from 2.0.5 onward is not.

Remediation

Update to version 2.0.5, or a newer patched version

How does WordSec protect against this?

An attacker needs Author access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: MailerPress 2.0.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-8599https://www.wordfence.com/threat-intel/vulnerabilities/id/c52cadb2-703f-4aad-85f2-aec1dd4befdchttps://nvd.nist.gov/vuln/detail/CVE-2026-8599

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C