WordPress security changelog
CRITICAL CVE-2026-18431 Deferred

Avada and Fusion Builder permit unauthenticated arbitrary file write

Avada through 7.16 combined with Fusion Builder through 3.16 contains an unauthenticated arbitrary-file-write chain. When both components are active and suitable administrator-authored content exists, an attacker can write and execute arbitrary PHP, resulting in complete site compromise.

CVE / CNA score 9.8 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Multiple WordPress plugins and themes
Plugin slug
avada
Affected
See vendor advisory
Safe version
See mitigation notes
Published
Aug 26, 2026
Weakness
CWE-862 — Missing Authorization

This CVE was published Aug 26, 2026 and is one of 22 known issues for this theme.

Update, patch or deactivate.

No fixed release is identified. Update both Avada and Fusion Builder when confirmed patches are available; until then, deactivate the affected combination when warranted and inspect server files, administrator content, accounts, and logs for compromise.

No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Technical description

The Avada theme for WordPress is vulnerable to Arbitrary File Write in all versions up to, and including, 7.16 when the Fusion Builder plugin is installed and active in versions up to, and including, 3.16. This is due to a chain of authorization and input validation weaknesses across the two components that makes it possible for unauthenticated attackers to write attacker-controlled files to the server. This can be used to create and execute arbitrary PHP files, resulting in remote code execution and complete site compromise. Successful exploitation requires both Avada and Fusion Builder to be installed and active, as well as certain administrator-authored content to be present.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary and upstream sources