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Vulnerability · Published May 21, 2026 · Assigned by Wordfence

CVE-2026-6279Avada (Fusion) Builder <= 3.15.2 - Unauthenticated Remote Code Execution via PHP Function Injection via 'render_logics' Shortcode Attribute via Widget AJAX Handler

Critical 9.8

In plain English

A critical-severity injection in Avada (Fusion) Builder from themefusion. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 9.9% (higher than 96% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei, public proof-of-concept code.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)9.9%top 4.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack tooling2Nuclei, Public PoC

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.

Affected products (as reported)

VendorProductVersions
themefusion Avada (Fusion) Builder 0 – through 3.15.2

Weakness: CWE-74 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References