# FireBox <= 3.1.15 - Unauthenticated Reflected Cross-Site Scripting via Smart Tags

- **ID:** WPSEC-2026-2794
- **Plugin:** FireBox – WooCommerce Popup Builder, Exit Intent Popup, Email Optin & Cart Abandonment (`firebox`), https://wordpress.org/plugins/firebox/
- **Affected versions:** all versions before 3.1.16
- **Fixed in:** 3.1.16 (Update to 3.1.16 or later.)
- **Severity:** Medium 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-11-10)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/firebox
- **Fix released:** 2026-11-09
- **Published:** 2026-11-10
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2794/

## Description

The FireBox plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the {querystring.*}, {cookie.*}, {post.*} and {client.useragent} Smart Tags in all versions up to, and including, 3.1.15 due to insufficient input sanitization and output escaping. Values sent by a visitor were only stripped of HTML tags without encoding quotes (and the User-Agent value was returned without any sanitization), and Smart Tags are replaced after campaign content has been rendered and escaped, so a value placed inside an HTML attribute could break out of it. This makes it possible for unauthenticated attackers to inject arbitrary web scripts into pages containing a campaign that uses these Smart Tags, which execute if they can successfully trick a user into performing an action such as clicking on a crafted link.

## References

- https://wpsec.com/vuln/WPSEC-2026-2794/
- https://plugins.svn.wordpress.org/firebox/tags/3.1.16/
- https://wordpress.org/plugins/firebox/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2794/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.