CVE-2026-6279

CRITICAL

Avada (Fusion) Builder <= 3.15.2 - Remote Code Execution via PHP Function Injection

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 4 public exploits for CVE-2026-6279. PoCs published by 87achrafg-stack, zycoder0day, xxconi.

AI-analyzed exploit summary This Python script exploits CVE-2026-6279, an unauthenticated RCE vulnerability in Avada Builder <= 3.15.2 via call_user_func() abuse. It automates nonce extraction, Cloudflare bypass, and payload delivery for RCE.

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.

Exploits (4)

github WORKING POC 1 stars
by 87achrafg-stack · pythonpoc
https://github.com/87achrafg-stack/CVE-2026-6279.py

This Python script exploits CVE-2026-6279, an unauthenticated RCE vulnerability in Avada Builder <= 3.15.2 via call_user_func() abuse. It automates nonce extraction, Cloudflare bypass, and payload delivery for RCE.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Avada Builder <= 3.15.2
No auth needed
Prerequisites: Target must have Avada Builder <= 3.15.2 installed · Public page with fusion_post_cards or fusion_table_of_contents shortcode
devstral-2 · analyzed Jun 13, 2026 Full analysis →
github WORKING POC
by 87achrafg-stack · pythonpoc
https://github.com/87achrafg-stack/CVE-2026-6279

This repository contains a functional Python exploit for CVE-2026-6279, targeting an unauthenticated RCE vulnerability in Avada Builder <= 3.15.2 via a call_user_func() injection chain. The exploit includes detailed nonce extraction logic and payload delivery mechanisms.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Avada Builder <= 3.15.2
No auth needed
Prerequisites: Target must have Avada Builder <= 3.15.2 installed · Public page with specific shortcodes (fusion_post_cards or fusion_table_of_contents)
devstral-2 · analyzed Jun 13, 2026 Full analysis →
github WORKING POC
by zycoder0day · pythonpoc
https://github.com/zycoder0day/CVE-2026-6279

This repository contains a functional exploit for CVE-2026-6279, targeting Avada Builder <= 3.15.2. The exploit leverages a deterministic nonce, unauthenticated AJAX endpoint, and deserialization to achieve RCE via call_user_func() without an allowlist.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Avada Builder (Fusion Builder) <= 3.15.2
No auth needed
Prerequisites: Target must be running Avada Builder <= 3.15.2 · AJAX endpoint must be accessible
devstral-2 · analyzed May 23, 2026 Full analysis →
nomisec WORKING POC
by xxconi · poc
https://github.com/xxconi/CVE-2026-6279

This repository contains a functional exploit for CVE-2026-6279, an unauthenticated RCE vulnerability in Avada Builder. The exploit retrieves a nonce from the target site and crafts a malicious payload to execute arbitrary commands via PHP functions like 'system' or 'exec'.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Avada Builder (WordPress) <= 3.15.2
No auth needed
Prerequisites: Target must be running Avada Builder <= 3.15.2 · fusion_load_nonce must be retrievable from the homepage
devstral-2 · analyzed May 23, 2026 Full analysis →

Scores

CVSS v3 9.8
EPSS 0.0014
EPSS Percentile 33.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-74
Status published
Products (1)
themefusion/Avada (Fusion) Builder < 3.15.2
Published May 21, 2026
Tracked Since May 21, 2026