Avada <= 7.16 and Fusion Builder <= 3.16 - Unauthenticated Remote Code Execution via Arbitrary File Write
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-862.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ThemeFusion | Avada (Fusion) Builder | up to 3.16 | — | No fix listed | CNA |
| ThemeFusion | Avada | Website Builder For WordPress & WooCommerce | up to 7.16 | — | No fix listed | CNA |
- Avada (Fusion) Builder VendorThemeFusion Affected up to 3.16 Fixed in — No fix listed CNA
- Avada | Website Builder For WordPress & WooCommerce VendorThemeFusion Affected up to 7.16 Fixed in — No fix listed CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:theme-fusion:avada:*:*:*:*:*:*:*:* | — | — | ThemeFusion |
- cpe:2.3:a:theme-fusion:avada:*:*:*:*:*:*:*:* Versions — — ·ThemeFusion
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-18431
- 2026-10-03 Alias added: GHSA-hm9x-g2wh-6xw7
References
More ThemeFusion vulnerabilities
- TI-2022-01267 Fusion Builder < 3.6.2 - Unauthenticated SSRF CVSS 3.1CRITICAL 9.8
- TI-2026-05505 Injection in ThemeFusion Avada Builder CVSS 3.1CRITICAL 9.8
- TI-2024-02175 Avada <= 7.11.6 - Unauthenticated Sensitive Information Exposure via Form Uploads Directory Listing CVSS 3.1MEDIUM 5.3
- TI-2024-12389 Avada Theme <= 7.11.13 - Unauthenticated Arbitrary Shortcode Execution CVSS 3.1CRITICAL 9.8
- TI-2026-07656 Avada (Fusion) Builder <= 3.15.3 - Unauthenticated Arbitrary File Deletion via Form Entry Value CVSS 3.1CRITICAL 9.1
- TI-2026-39098 WordPress Fusion Builder plugin <= 3.15.4 - PHP Object Injection vulnerability CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-18431 · CVE Program
- CVE-2026-18431 · NVD
- FIRST EPSS
- GHSA-hm9x-g2wh-6xw7 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences