---
id: CVE-2025-9129
title: >-
  The Flexi plugin for WordPress is vulnerable to Stored Cross-Site Scripting
  via the plugin for WordPress's flexi-form-tag shortcode in all versions up to,
  and including, 4.28 due to insufficient input sanitization and output escaping
  on …
summary: >-
  The Flexi plugin for WordPress is vulnerable to Stored Cross-Site Scripting
  via the plugin for WordPress's flexi-form-tag shortcode in all versions up to,
  and including, 4.28 due to insufficient input sanitization and output escaping
  on …
severity: medium
cvss: 6.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2025-10-03'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T22:10:00.563'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-9129'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/flexi/trunk/includes/class-flexi-form.php#L572
    label: security@wordfence.com
  - url: 'https://wordpress.org/plugins/flexi/#developers'
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/ccfd4949-07ae-48b6-9aa2-82fd6b1bf692?source=cve
    label: security@wordfence.com
tags:
  - nvd
epss: 0.00241
epssPercentile: 0.14042
ingestedAt: '2026-10-08T22:11:53.764Z'
---

## Overview

The Flexi plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin for WordPress's flexi-form-tag shortcode in all versions up to, and including, 4.28 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, 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.