XSS in Themefusion Avada (Fusion) Builder
CVE-2026-16654
The Avada (Fusion) Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'size' Shortcode Attribute in all versions up to, and including, 3.15.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. WordPress's wp_kses_post filter does not neutralize the payload because the injected content resides entirely within a shortcode attribute string containing no HTML angle brackets, causing kses to pass it through unchanged at save time.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (5.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-16654?
- CVE-2026-16654 is a medium-severity vulnerability in Themefusion Avada (Fusion) Builder, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-08-28.
- How severe is CVE-2026-16654?
- Medium severity. CVSS v3 base score is 6.4 out of 10.