The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the `wp_conditional_tags` case in `Fusion_Builder_Conditional_Render_Helper::get_value()` passing attacker-controlled values from a base64-decoded JSON blob directly to `call_user_func()` without any allowlist validation. This is exploitable by unauthenticated attackers through the `fusion_get_widget_markup` AJAX endpoint, which is registered for non-privileged (unauthenticated) users via `wp_ajax_nopriv_fusion_get_widget_markup`. The endpoint is protected only by a nonce (`fusion_load_nonce`), but this nonce is generated for user ID 0 and is deterministically exposed in the JavaScript output of any public-facing page containing a Post Cards (`[fusion_post_cards]`) or Table of Contents (`[fusion_table_of_contents]`) element. This makes it possible for unauthenticated attackers to execute arbitrary code on affected sites.
CVE-2026-6279 is a critical severity with CVSS 9.8 Remote Code Execution issue affecting the Plugin Avada (Fusion) Builder. It affects Versions up to 3.15.2 and is fixed in 3.15.3.
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CVE-2026-6279 is tracked for the Plugin Avada (Fusion) Builder as critical severity with CVSS 9.8. The affected range is Versions up to 3.15.2. Update Avada (Fusion) Builder to 3.15.3 or newer where that version is compatible with the site.
Search engines and operators need more than a title. This page exposes the identifier, affected range, patch evidence, and source coverage that make the vulnerability actionable.
This report has a CVE identifier, which makes it suitable for focused search and vulnerability triage workflows.
Affected version data gives operators a concrete comparison point against installed WordPress software.
A fixed version is present, so the page can answer update and remediation intent directly.
External references are available for source validation, advisory review, and incident notes.
Use these checks when converting this record into a patch ticket, incident note, or risk acceptance decision.
Inventory the installed Plugin package and compare its version with Versions up to 3.15.2.
Confirm Avada (Fusion) Builder is updated to 3.15.3 or newer.
Review references and CVSS vector details for exploitability, authentication requirements, and exposure path.
After patching, re-run vulnerability monitoring and keep the related plugin or theme hub under review for follow-up CVEs.
| Software Type | Plugin |
|---|---|
| Software Slug |
fusion-builder
View on wordpress.org
|
| CVE | CVE-2026-6279 |
| Patched Versions |
3.15.3
|
| Affected Versions |
Versions up to 3.15.2
|
These internal links group the same WordPress plugin by CVE, issue type, severity, and patch status so operators and search engines can connect the full vulnerability cluster.
Fusion Builder <= 3.11.1 - Authenticated (Subscriber+) SQL Injection
Fusion Builder <= 3.6.1 & Avada <= 7.6.1 - Unauthenticated Server-Side Request Forgery
Avada Builder <= 3.15.1 - Unauthenticated SQL Injection via 'product_order' Parameter
Avada Builder <= 3.11.13 - Unauthenticated Arbitrary Shortcode Execution
Avada Builder <= 3.15.2 - Authenticated (Subscriber+) Arbitrary File Read via 'custom_svg' Shortcode Parameter
Fusion Builder <= 3.11.1 - Cross-Site Request Forgery
Avada (Fusion) Builder <= 3.15.2 - Authenticated (Subscriber+) Stored Cross-Site Scripting via Multiple Shortcodes
Avada (Fusion) Builder <= 3.14.1 - Authenticated (Contributor+) Stored Cross-Site Scripting
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