---
id: CVE-2025-13993
title: >-
  The MailerLite – Signup forms (official) plugin for WordPress is vulnerable to
  Stored Cross-Site Scripting via the 'form_description' and 'success_message'
  parameters in versions up to, and including, 1.7.16 due to insufficient input
  san…
summary: >-
  The MailerLite – Signup forms (official) plugin for WordPress is vulnerable to
  Stored Cross-Site Scripting via the 'form_description' and 'success_message'
  parameters in versions up to, and including, 1.7.16 due to insufficient input
  san…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2025-12-12'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T20:10:01.970'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-13993'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/official-mailerlite-sign-up-forms/tags/1.7.14/src/Controllers/AdminController.php#L179
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/official-mailerlite-sign-up-forms/tags/1.7.14/src/Controllers/AdminController.php#L224
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/official-mailerlite-sign-up-forms/tags/1.7.14/src/Views/CustomForm.php#L38
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/official-mailerlite-sign-up-forms/tags/1.7.14/src/Views/CustomForm.php#L94
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset/3416100/official-mailerlite-sign-up-forms/trunk/src/Controllers/AdminController.php
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/8c37cc28-fde0-45c6-b49c-d6dfb296c4a5?source=cve
    label: security@wordfence.com
tags:
  - nvd
epss: 0.00343
epssPercentile: 0.25669
ingestedAt: '2026-10-07T20:46:46.898Z'
---

## Overview

The MailerLite – Signup forms (official) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'form_description' and 'success_message' parameters in versions up to, and including, 1.7.16 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator access or higher, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

## Remediation

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