---
id: CVE-2026-17577
title: >-
  The SSL Zen plugin for WordPress is vulnerable to Reflected Cross-Site
  Scripting via the 'uri' (and 'host') parameters in versions up to, and
  including, 4.7.42
summary: >-
  The SSL Zen plugin for WordPress is vulnerable to Reflected Cross-Site
  Scripting via the 'uri' (and 'host') parameters in versions up to, and
  including, 4.7.42. The ssl_zen_messages::getMessages() function builds the
  'token_missmatch' me…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: sslzen
product: SSL Zen — SSL Certificate Installer & HTTPS Redirects
affected:
  - ssl_zen_ssl_certificate_installer_https_redirects <= 4.7.42
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T13:08:08.163'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-17577'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.14/ssl_zen/classes/class.ssl_zen_admin.php#L863
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.14/ssl_zen/classes/class.ssl_zen_messages.php#L44
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.42/ssl_zen/classes/class.ssl_zen_admin.php#L863
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/ssl-zen/tags/4.7.42/ssl_zen/classes/class.ssl_zen_messages.php#L44
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?reponame=&old=3701590%40ssl-zen&new=3701590%40ssl-zen
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/20816039-0b1c-420a-b5f4-b5370d0331da?source=cve
    label: security@wordfence.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-25T10:31:30.444491Z'
ingestedAt: '2026-09-25T08:01:56.747Z'
---

## Overview

The SSL Zen plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'uri' (and 'host') parameters in versions up to, and including, 4.7.42. The ssl_zen_messages::getMessages() function builds the 'token_missmatch' message using base64_decode(sanitize_text_field($_REQUEST['uri'])) and (optionally) base64_decode(sanitize_text_field($_REQUEST['host'])). sanitize_text_field() cannot strip HTML/JavaScript that is hidden inside a base64-encoded blob, and the resulting decoded raw HTML is echoed unescaped by showMessage() . This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.