Critical

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

  • Disclosed: 20.05.2026
  • Updated: 11.10.2026 10:22

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 software

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PlatformPackageVulnerable versionsFixed in
WordPress plugin Avada (Fusion) Builder <= 3.15.2 3.15.3

References

CVSS score 9.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-74
Platform
WordPress
Package
Avada (Fusion) Builder
Disclosed
20.05.2026
Updated
11.10.2026 10:22

Sources and licenses

Wordfence Intelligence - 5dc72d78-d47c-4b36-8d69-8672e15ddf8c - Wordfence Intelligence

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Subject to this Agreement, Company hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute the Service. Any copy you make for such purposes is authorized provided that you reproduce Company’s copyright designation, this license, and the license of any disclosed Company licensor in any such copy.

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Vulnerability history: Avada (Fusion) Builder

All published vulnerabilities of this package (WordPress plugin), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (30) in the archive
Total entries
30
First → latest
04.2022 10.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 4
  • High 7
  • Medium 19

Disclosures per year

  1. 2022: 1
  2. 2023: 4
  3. 2024: 2
  4. 2025: 5
  5. 2026: 18
Severity:
  1. Avada (Fusion) Builder <= 3.15.2 - Unauthenticated Remote Code Execution via PHP Function Injection via 'render_logics' Shortcode Attribute via Widget AJAX Handler this entry
    Critical · 9.8 CVE-2026-6279 <= 3.15.2 3.15.3
  2. High · 7.3 CVE-2024-13345 <= 3.11.13 3.11.14
  3. High · 8.8 CVE-2023-39309 <= 3.11.1 3.11.2

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