CVE-2026-6279
CWE-74Published: May 21, 2026· Updated: May 21, 2026
Official 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.
Risk Analysis
This critical vulnerability in the Avada Builder (fusion-builder) plugin for WordPress allows unauthenticated remote code execution. The flaw stems from improper handling of attacker-controlled values passed directly to a PHP function, enabling arbitrary code execution. A CVSS score of 9.8 highlights the severe impact, as it can lead to complete compromise of the affected WordPress site.
No public exploit is currently known for this vulnerability. The vulnerability is remotely exploitable by unauthenticated attackers over the network with low attack complexity.
Users of the Avada Builder plugin should update to a version beyond 3.15.2 immediately. Regularly review and update all WordPress plugins to their latest secure versions.
Technical Analysis
CVE-2026-6279 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (12)
Quick Facts
Related CVEs (CWE-74)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-6279 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts