Avada Builder Plugin RCE and XSS Vulnerabilities

Unauthenticated remote code execution in the Avada Builder (fusion-builder) WordPress plugin versions up to and including 3.15.2 allows attackers to execute arbitrary PHP on affected sites by abusing an unsanitized call_user_func() invocation reachable through a public AJAX endpoint. Wordfence-reported issue affects any WordPress site running the Avada theme stack that exposes a Post Cards or Table of Contents element on a public page, since the protecting nonce is deterministically leaked in the page's JavaScript. No public exploit identified at time of analysis, but the CVSS 9.8 rating and trivial precondition (visiting one page that emits the nonce) make this high-priority.

Stored Cross-Site Scripting in Avada (Fusion) Builder for WordPress (all versions through 3.15.2) allows authenticated attackers with Subscriber-level access to persist malicious JavaScript via unsanitized shortcode parameters. The injected scripts execute in the browser of any user - typically an administrator - who views a page rendering dynamic user data such as biographical information sourced through the plugin's Dynamic Data feature. With CVSS Scope set to Changed (S:C), successful exploitation crosses the victim's security boundary, enabling session hijacking or privilege escalation against higher-privileged users. No public exploit code or CISA KEV listing has been identified at time of analysis.