Critical Avada WordPress Theme Flaw Enables Zero-Click Remote Code Execution

A critical chain of vulnerabilities in the popular Avada WordPress theme could allow an unauthenticated attacker to execute arbitrary PHP code on a vulnerable server without any user interaction.

Tracked as CVE-2026-18431, the vulnerability chain combines six security flaws into a zero-click remote code execution (RCE) attack. The issue has received a critical severity rating of 9.8 out of 10.

The attack exploits weaknesses in authorization, input validation, trust boundaries, and file handling. An attacker must trigger the flaws in a specific sequence to gain the ability to execute arbitrary PHP code on the affected WordPress website.

A successful exploit could result in a complete website compromise. Attackers could install malware, access sensitive databases, redirect visitors to malicious websites, modify site content, or create unauthorized administrator accounts.

CVE-2026-18431 affects Avada versions through 7.16 and Fusion Builder plugin versions through 3.16, according to researchers from Defiant’s Wordfence team in a report published Tuesday.

ThemeFusion, the developer of Avada and Fusion Builder, has released security updates for the vulnerability. Wordfence has not yet disclosed the full technical details, giving website administrators time to patch their installations. Researchers have published only a high-level overview of the exploit chain.

1. Expose attacker-controlled input through publicly accessible requests
2. Pass data submitted by an unauthenticated user to a restricted function
3. Invoke a privileged component outside its intended security context
4. Use request data to modify trusted application state
5. Reach administrative operations that are insufficiently protected
6. Bypass file-handling restrictions governing where files can be written

Despite the critical severity of CVE-2026-18431, exploitation requires both the vulnerable Avada theme and the vulnerable Fusion Builder plugin to be active on the target WordPress website.

Avada has sold more than 1 million copies, making it a widely deployed WordPress theme. However, the requirement for both vulnerable components to be installed and active limits the number of websites exposed to this particular attack chain.

Wordfence identified the six-step vulnerability chain with an internal agent framework called Argus. The system also generated proof-of-concept exploit code in approximately two hours.

Argus discovered and reproduced the vulnerability on July 30. Wordfence notified ThemeFusion on August 5, and the developer acknowledged the report on August 10. ThemeFusion released fixes in Avada 7.16.1 and Fusion Builder 3.16.1.

WordPress administrators should update Avada and Fusion Builder to the latest available versions as soon as possible. Websites that cannot be patched immediately should disable the affected components and review server, WordPress, and administrator activity for signs of compromise.

The overall prevention score can hide what happens after the initial access. If an attacker uses valid credentials, your defenses drop sharply.

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