CVE-2026-6279
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.16%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.16% probability · 81th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-74
- Source
- security@wordfence.com
References
- https://avada.com/documentation/avada-changelog/
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/class-fusion-builder.php#L7551
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1083
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1531
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/shortcodes/fusion-widget.php#L389
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/shortcodes/fusion-widget.php#L44
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/class-fusion-builder.php#L7551
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1083
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1531
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/shortcodes/fusion-widget.php#L389
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/shortcodes/fusion-widget.php#L44
- https://www.wordfence.com/threat-intel/vulnerabilities/id/5dc72d78-d47c-4b36-8d69-8672e15ddf8c?source=cve
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.