CVE-2026-6279 (GCVE-0-2026-6279)
Vulnerability from cvelistv5 – Published: 2026-05-21 04:27 – Updated: 2026-05-21 12:23
VLAI
EPSS
VEX
Title
Avada (Fusion) Builder <= 3.15.2 - Unauthenticated Remote Code Execution via PHP Function Injection via 'render_logics' Shortcode Attribute via Widget AJAX Handler
Summary
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.
Severity
9.8 (Critical)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-21 12:22 UTC
CWE
- CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Assigner
References
12 references
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| themefusion | Avada (Fusion) Builder |
Affected:
0 , ≤ 3.15.2
(semver)
|
guessed |
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