Injection in ThemeFusion Avada Builder
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the `wp_conditional_tags` case in `Fusion_Builder_Conditional_Render_Helper::get_value()` passing attacker-controlled values from a base64-decoded JSON blob directly to `call_user_func()` without any allowlist validation. This is exploitable by unauthenticated attackers through the `fusion_get_widget_markup` AJAX endpoint, which is registered for non-privileged (unauthenticated) users via `wp_ajax_nopriv_fusion_get_widget_markup`. The endpoint is protected only by a nonce (`fusion_load_nonce`), but this nonce is generated for user ID 0 and is deterministically exposed in the JavaScript output of any public-facing page containing a Post Cards (`[fusion_post_cards]`) or Table of Contents (`[fusion_table_of_contents]`) element. This makes it possible for unauthenticated attackers to execute arbitrary code on affected sites.
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 3.15.2 | — | No fix listed | CNA |
- Avada (Fusion) Builder VendorThemeFusion Affected up to 3.15.2 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-6279
- 2026-10-03 Alias added: GHSA-f53p-382v-8pj7
- 2026-10-23 EPSS moved to the 90th–95th percentile
- 2026-10-25 EPSS moved to the 95th–99th percentile
References
Other 12
- https://www.wordfence.com/threat-intel/vulnerabilities/id/5dc72d78-d47c-4b36-8d69-8672e15ddf8c?source=cve
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1531
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1531
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/shortcodes/fusion-widget.php#L44
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/shortcodes/fusion-widget.php#L44
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/shortcodes/fusion-widget.php#L389
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/shortcodes/fusion-widget.php#L389
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/class-fusion-builder.php#L7551
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/class-fusion-builder.php#L7551
- https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1083
- https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1083
- https://avada.com/documentation/avada-changelog/
More ThemeFusion vulnerabilities
- TI-2022-01267 Fusion Builder < 3.6.2 - Unauthenticated SSRF 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-2026-15146 Avada <= 7.16 and Fusion Builder <= 3.16 - Unauthenticated Remote Code Execution via Arbitrary File Write 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-2026-6279 · CVE Program
- CVE-2026-6279 · NVD
- FIRST EPSS
- GHSA-f53p-382v-8pj7 · 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