CVE-2026-57816
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 · uneditedImproper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in FunnelKit Funnel Builder by FunnelKit funnel-builder allows Reflected XSS.This issue affects Funnel Builder by FunnelKit: from n/a through <= 3.15.0.8.
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 confidenceReflected XSS vulnerability in FunnelKit Funnel Builder plugin for WordPress allows attackers to inject malicious scripts via unsanitized user input that gets reflected in web pages without proper output encoding.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
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 the FunnelKit Funnel Builder plugin versionLog into WordPress admin, navigate to Plugins > Installed Plugins, find FunnelKit Funnel Builder, and note the version number displayed. Alternatively, check the main plugin file in wp-content/plugins/funnel-builder/ or similar for the Version header.Affected if The displayed version is lower than 3.15.0.8 (e.g., 3.15.0.7, 3.14.x, etc.)
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Identify the vulnerable endpointReview your web server access logs for requests to FunnelKit-related PHP files (commonly in /?wc-ajax= or admin-ajax.php endpoints with funnelkit or funnels in the action parameter). Note which parameters accept user input.Affected if The site processes user input through FunnelKit AJAX endpoints without sanitization
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Test for reflected input without encodingSubmit a harmless test string (e.g., <script>alert('test')</script>) via GET or POST to the identified FunnelKit endpoint parameters. Inspect the HTTP response to see if the raw string appears unescaped in the HTML output.Affected if The test string appears literally (unescaped) in the response, indicating missing output encoding
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Review plugin source for missing escapingIf you have file access, locate the PHP file handling the identified endpoint. Search for the relevant $_GET or $_POST parameter usage and verify whether esc_html(), esc_attr(), or similar escaping functions are applied before output.Affected if The parameter value is output directly to HTML without passing through an escaping function
You are affected if the installed FunnelKit Funnel Builder version is below 3.15.0.8 AND user-supplied input is reflected in FunnelKit-generated pages without proper HTML escaping.
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 dataUpdate FunnelKit Funnel Builder to version 3.15.0.8 or later to obtain the patch. If immediate update is not possible, implement input validation and output escaping on affected parameters.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-57816 — 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-2026-57816 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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