Critical Avada WordPress theme flaw enables zero-click RCE

A critical vulnerability chain in the popular Avada theme for WordPress can be exploited by an unauthenticated attacker to execute arbitrary PHP code on the server. The exploit chains six security issues into a zero-click attack. The flaws are collectively tracked as CVE-2026-18431 and received a 9.8 critical severity score. The attack comprises exploits for authorization, input-validation, trust-boundary, and file-handling weaknesses, which must be executed in a specific order to enable arbitrary PHP code execution on a target server. Hackers who successfully exploit these vulnerabilities could fully compromise websites for malicious activities ranging from planting malware and accessing databases to redirecting visitors to malicious sites or adding rogue admin accounts. CVE-2026-18431 affects Avada versions up to 7.16 and Fusion Builder plugin versions up to 3.16, researchers at Defiant's Wordfence team say in a report on Tuesday. While ThemeFusion, the developer behind Avada and Fusion Builder, fixed the vulnerability, Wordfence is not sharing complete technical details to give administrators sufficient time to install the latest updates and has only provided the following attack chain overview: Although exploitation requires a vulnerable version of both the Avada theme and the Fusion Builder plugin to be active on the target website, Wordfence researchers clarified for BleepingComputer that "Fusion Builder is a required plugin for the Avada theme." "Therefore all sites r...