CVE-2026-104729: Avada (Fusion) Builder <= 3.16.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'tab_index' and 'empty_notice' Shortcode Attributes

Q: Who can exploit this issue?

An attacker needs an authenticated WordPress account with at least Contributor-level access. They can inject malicious script through the tab_index or empty_notice shortcode attributes.

Q: Who is exposed to the injected script?

The script executes whenever a user accesses a page containing the attacker’s injected shortcode. The issue has scope changed, so the vulnerable plugin can affect users viewing affected pages.

Q: Are default protections sufficient to block the payload?

No. The described wp_kses_post filtering does not remove the payload when dangerous characters are placed in shortcode attribute text between square brackets, because it treats that content as plain text rather than HTML markup.

Q: How can I check for possible exploitation?

Review pages and other content created or edited by Contributor-level and higher accounts for Avada Builder shortcodes using the tab_index or empty_notice attributes. Inspect those attribute values for unexpected script-like or otherwise suspicious content.

Published Oct 28, 2026

Updated

The Avada (Fusion) Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'tabindex, emptynotice' parameter in all versions up to, and including, 3.16.2 due to insufficient input sanitization and output escaping. 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. wpksespost does not strip the payload on save because the dangerous characters reside within shortcode attribute text between square brackets, which kses treats as plain text rather than HTML markup.

Affected Software

1 affected component

ThemeFusion Avada (Fusion) Builder<=3.16.2

Event History

Oct 28, 2026

CVE Published

via MITRE·06:45 AM

Data Sourced

via MITRE·06:45 AM

DescriptionSeverityWeakness

Frequently Asked Questions

Who can exploit this issue?

An attacker needs an authenticated WordPress account with at least Contributor-level access. They can inject malicious script through the tab_index or empty_notice shortcode attributes.

Who is exposed to the injected script?

The script executes whenever a user accesses a page containing the attacker’s injected shortcode. The issue has scope changed, so the vulnerable plugin can affect users viewing affected pages.

Are default protections sufficient to block the payload?

No. The described wp_kses_post filtering does not remove the payload when dangerous characters are placed in shortcode attribute text between square brackets, because it treats that content as plain text rather than HTML markup.

How can I check for possible exploitation?

Review pages and other content created or edited by Contributor-level and higher accounts for Avada Builder shortcodes using the tab_index or empty_notice attributes. Inspect those attribute values for unexpected script-like or otherwise suspicious content.

CVE-2026-104729: Avada (Fusion) Builder <= 3.16.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'tab_index' and 'empty_notice' Shortcode Attributes

Affected Software

Event History

Frequently Asked Questions

Who can exploit this issue?

Who is exposed to the injected script?

Are default protections sufficient to block the payload?

How can I check for possible exploitation?

Company

Resources

Contact

Frequently Asked Questions

Who can exploit this issue?

Who is exposed to the injected script?

Are default protections sufficient to block the payload?

How can I check for possible exploitation?