Critical Avada WordPress theme flaw enables zero-click RCE
Critical vulnerability in Avada WordPress theme can be exploited for arbitrary PHP code execution. CVE-2026-18431 affects Avada versions up to 7.16 and Fusion Builder plugin versions up to 3.16.
Intelligence analysis by Qwen 2.5 (3B)

A critical vulnerability in the Avada WordPress theme allows attackers to execute arbitrary PHP code, affecting versions up to 7.16 and 3.16 of the Fusion Builder plugin.
A bad guy can trick a website into running bad code, like a virus, by sending a special message. If both the theme and plugin are old and not fixed, the website could get hacked and the bad guy could do anything they want on the site.
Analysis
{"heading":"The Exploit Chain","subheading":"Step-by-Step Attack Process","paragraph_1":"The vulnerability in Avada and Fusion Builder plugins can be exploited through a series of six steps, each requiring specific conditions to be met.","paragraph_2":"First, attackers expose attacker-controlled input through a public request. Then, they pass that input to functionality restricted from anonymous users. Next, they invoke a privileged component outside its intended context.","paragraph_3":"Subsequently, attackers use request data to influence trusted state and access an insufficiently protected administrative operation. Finally, they bypass file-handling restrictions to write and execute code on the server.","paragraph_4":"The vulnerability affects Avada versions up to 7.16 and Fusion Builder plugin versions up to 3.16. Both themes and plugins must be vulnerable for the attack to succeed.","paragraph_5":"Wordfence, the security team behind Avada and Fusion Builder, discovered the vulnerability and provided an overview of the attack chain. They also shared proof-of-concept exploit code.","paragraph_6":"ThemeFusion, the developer behind Avada and Fusion Builder, fixed the vulnerability and released updates in Avada 7.16.1 and Fusion Builder 3.16.1.","paragraph_7":"Once attackers have valid credentials, they can execute 37% of their actions, highlighting the importance of strong authentication and prevention measures."}
Key points
- Avada and Fusion Builder plugins are affected by a critical vulnerability
- The vulnerability can be exploited to execute arbitrary PHP code
- Both themes and plugins must be vulnerable for the attack to succeed
- Wordfence discovered and shared the vulnerability and attack chain
- ThemeFusion released updates to fix the vulnerability
Fixing the vulnerability in Avada and Fusion Builder will make it harder for attackers to exploit the flaw, improving website security.
If the vulnerability is not fixed, attackers could still exploit it, leading to more serious security issues.


