ReviewCritical

CVE-2026-18431

themefusion Avada (Fusion) Builder, Avada | Website Builder For WordPress & WooCommerce

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...

CVSS
9.8
EPSS
0.64%
48.2% percentile
CISA KEV
Not listed
Published
2026.08.26
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.64%
Technical severityCVSS 9.8

Vulnerability overview

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...

Affected product and versions

Product
themefusion Avada (Fusion) Builder, Avada | Website Builder For WordPress & WooCommerce
Affected versions
<= 3.16, <= 7.16
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that themefusion Avada (Fusion) Builder, Avada | Website Builder For WordPress & WooCommerce and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-862