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)

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.002 (3.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 3.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-16654: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000

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.