Popup Builder <= 4.4.5 - Unauthenticated Stored Cross-Site Scripting via Subscription Form Name Fields
- ID
- WPSEC-2026-1351
- Plugin
- Popup Builder – Create highly converting, mobile friendly marketing popups. (popup-builder)
- Affected
- from 4.1.1 before 4.4.6
- Remediation
- Update to 4.4.6 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- Weakness
- CWE-79
- Usage
- Plugin High · Affected versions Medium among sites WPSec scans, 2026-10-21
- Attack surface
- Popup Builder on WPSec AttackSurface
- Fix released
- Published
Description
The Popup Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the subscription form first name and last name fields in versions 4.1.1 through 4.4.5, due to insufficient input sanitization and output escaping. Names were stored after sanitize_text_field() only, which keeps a '<' followed by whitespace, and were printed on the admin Subscribers page through wp_kses() with an allowlist that permits script tags and onclick attributes, so the stored text becomes a real tag again. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator views the Subscribers page.
References
- https://wpsec.com/vuln/WPSEC-2026-1351/
- https://plugins.svn.wordpress.org/popup-builder/tags/4.4.6/
- https://wordpress.org/plugins/popup-builder/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
This advisory as JSON or Markdown · All advisories: JSON, RSS