WordPress E&P Forms Plugin Stored XSS Injection Flaw

The WP Cost Estimation & Payment Forms Builder (E&P Forms) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'customerInfos' parameter in all versions up to, and including, 10.5.97 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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

The WP Cost Estimation & Payment Forms Builder plugin contains a stored cross-site scripting (XSS) vulnerability in the 'customerInfos' parameter affecting all versions through 10.5.97. Because the plugin fails to properly sanitize user input and escape output, unauthenticated attackers can inject malicious JavaScript that persists in the database and executes in the browsers of any user viewing the affected page. This is particularly dangerous for WordPress sites using this popular plugin, as the attack requires no authentication and impacts all site visitors, potentially leading to credential theft, session hijacking, malware distribution, or defacement.

Casky's 754 mapped security skills leveraging Claude's extended reasoning capabilities detect this vulnerability pattern by identifying the attack chain across MITRE ATT&CK techniques: TA0001 (Initial Access) through unauthenticated injection points, and TA0043 (Reconnaissance) for payload delivery analysis. Practitioners using Casky would see findings highlighting inadequate input validation on the 'customerInfos' parameter, detection of unescaped output rendering user-controlled data in HTML/JavaScript contexts, and stored payload persistence indicators. The platform's skill set would surface the gap between user input acceptance and secure output encoding, correlating this with known XSS exploitation patterns and providing specific remediation guidance around WordPress sanitization functions like sanitize_text_field() and escaping functions like esc_attr() or wp_kses_post().

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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-2026-9253.

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-2026-9253

Casky has 322 skills that investigate the attack patterns behind CVE-2026-9253. Run one and get CVSS-scored findings in 3 minutes.

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