Avada <= 7.16 and Fusion Builder <= 3.16 - Unauthenticated Remote Code Execution via Arbitrary File Write (CVE-2026-18431) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-18431

Avada <= 7.16 and Fusion Builder <= 3.16 - Unauthenticated Remote Code Execution via Arbitrary File Write

Answer in brief

CVE-2026-18431 records a Unknown severity vulnerability in Avada <= 7.16 and Fusion Builder <= 3.16 - Unauthenticated Remote Code Execution via Arbitrary File Write. The current sources do not mark it as known exploited. The current feed maps themefusion/Avada (Fusion) Builder (generic), ThemeFusion/Avada | Website Builder For WordPress & WooCommerce (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 26, 2026Updated Aug 26, 2026Source checked Aug 26, 2026First seen by HOL Aug 26, 2026Material review Aug 26, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps themefusion/Avada (Fusion) Builder (generic), ThemeFusion/Avada | Website Builder For WordPress & WooCommerce (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
themefusion/Avada (Fusion) Buildergeneric	0	Not reported
ThemeFusion/Avada \| Website Builder For WordPress & WooCommercegeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for themefusion/Avada (Fusion) Builder, ThemeFusion/Avada | Website Builder For WordPress & WooCommerce.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 26, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 26, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 26, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.