Unauthenticated Reflected XSS in FunnelKit WordPress Plugin

The FunnelKit WordPress plugin before 3.15.0.6 does not escape a user-supplied parameter before reflecting it into the HTML response of one of its page-builder AJAX actions, allowing unauthenticated attackers to perform Reflected Cross-Site Scripting against logged-in users who open a crafted page. The affected action is only registered when the Divi /builder is active.

Casky was already ahead

This CVE exploits attack patterns that Casky's 322matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

FunnelKit, a popular WordPress plugin for funnel and landing page creation, contains a reflected cross-site scripting (XSS) vulnerability in its page-builder AJAX actions when the Divi builder is active. The vulnerability exists because user-supplied parameters are reflected directly into HTML responses without proper escaping, allowing attackers to inject malicious scripts. This affects unauthenticated attackers targeting logged-in WordPress users who click specially crafted links, potentially leading to session hijacking, credential theft, or malicious actions performed on behalf of the victim. With 322 mapped security skills and a CVSS score of 7.1, this represents a significant risk to WordPress installations running FunnelKit before version 3.15.0.6 alongside the Divi builder.

Casky.ai's 754 security skills mapped to MITRE ATT&CK enable detection of the attack patterns underlying this CVE through two primary techniques: TA0001 (Initial Access) via social engineering through crafted phishing links, and TA0043 (Reconnaissance) involving parameter fuzzing and endpoint discovery. When practitioners use Claude AI's extended reasoning capabilities within Casky, they can identify suspicious AJAX request patterns targeting FunnelKit's builder endpoints, detect unescaped parameter reflection in HTTP responses, and recognize script injection attempts in user-controlled inputs. Security findings would surface anomalies such as unexpected HTML/JavaScript in page-builder AJAX responses, repeated parameter manipulation attempts on vulnerable endpoints, and evidence of stored or reflected payloads—enabling teams to patch vulnerable versions and implement Web Application Firewall (WAF) rules before exploitation occurs.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

322 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-12978.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

Investigate the attack patterns behind CVE-2026-12978

Casky has 322 skills that investigate the attack patterns behind CVE-2026-12978. Run one and get CVSS-scored findings in 3 minutes.

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