Fusion BuilderWordPress extension · Avada
CVE-2023-39311
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedCross-Site Request Forgery (CSRF) vulnerability in ThemeFusion Fusion Builder.This issue affects Fusion Builder: from n/a through 3.11.1.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceCross-Site Request Forgery (CSRF) vulnerability in ThemeFusion Fusion Builder (WordPress page builder plugin) allows attackers to induce authenticated administrators to perform unintended actions such as modifying page layouts, saving settings, or executing builder functions via forged requests.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Fusion BuilderWordPress extension
<= 3.11.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Locate Fusion Builder plugin versionIn WordPress admin, go to Plugins > Installed Plugins and find 'Avada Fusion Builder' or 'Fusion Builder' - the version number is displayed below the plugin name. Alternatively, check the main plugin file header via file manager or WP-CLI: wp plugin get fusion-builder --format=versionAffected if Version displayed is 3.11.1 or lower
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Confirm Avada theme/plugin bundle versionIf using Avada theme, check Avada > Theme Options > About Avada for the bundled Fusion Builder version. The vulnerability affects Fusion Builder <= 3.11.1 regardless of whether standalone or bundled.Affected if Fusion Builder component version is 3.11.1 or lower
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Identify exposed admin actionsThe vulnerability affects any state-changing admin action via Fusion Builder including: modifying page layouts (fusion_builder_reset_shortcode), saving settings, and executing builder functions through AJAX endpoints at /wp-admin/admin-ajax.phpAffected if Site has Fusion Builder active and allows admin users to access the builder interface
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Check for anti-CSRF protectionsInspect source code of Fusion Builder AJAX handlers (typically in includes/fusion-builder-frontend.php or similar files) for presence of wp_verify_nonce or check_admin_referer calls before processing requests. Missing nonce validation on sensitive endpoints indicates vulnerability is present.Affected if Code review reveals missing nonce validation on builder AJAX actions and the installed version is 3.11.1 or lower
You are affected if running Avada Fusion Builder version 3.11.1 or lower and the plugin handles authenticated admin actions without CSRF protection.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply vendor patch/upgrade to Fusion Builder version 3.11.2 or later; ensure all state-changing forms and AJAX endpoints implement anti-CSRF nonce validation and SameSite cookie attributes.
Fix this in Fusion Builder
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-39311 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-39311 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data