MW WP Form Plugin Stored XSS via Post ID Parameter

The MW WP Form plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'post_id' parameter in all versions up to, and including, 5.1.7 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. The CSRF gate protecting form submission (MW_WP_Form_Csrf) is bypassable by any unauthenticated visitor who first loads the public form page to obtain a valid double-submit cookie, leaving no effective barrier to storing malicious payloads.

Casky was already ahead

This CVE exploits attack patterns that Casky's 323matched 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 MW WP Form plugin for WordPress contains a stored cross-site scripting (XSS) vulnerability affecting all versions up to 5.1.7. Unauthenticated attackers can inject malicious scripts through the 'post_id' parameter, which are then executed whenever users access the compromised page. This vulnerability is particularly dangerous because it persists in the database, affecting all subsequent visitors rather than requiring individual phishing attempts. WordPress sites using this popular form plugin are at immediate risk, as the vulnerability requires no authentication and the CSRF protections can be bypassed by any visitor, making exploitation trivial for threat actors.

Casky's 323 mapped security skills leverage Claude's extended reasoning to detect the attack patterns associated with MITRE techniques TA0001 (Reconnaissance) and TA0043 (Reconnaissance) by identifying indicators of input validation failures and output encoding gaps. Practitioners using Casky would observe findings highlighting insufficient sanitization of user-supplied parameters combined with unescaped output rendering in page contexts—the hallmark signatures of stored XSS. The platform would flag the specific attack vector (post_id parameter injection), correlate it with CWE-79 patterns, and surface detection logic that identifies both the injection point and the persistence mechanism in WordPress database structures, enabling security teams to quickly prioritize remediation and hunt for evidence of exploitation in their environments.

Live Threat IntelligenceComing soon

Casky Risk Score

—

EPSS Probability

—

Shodan Exposure

—

GreyNoise Signal

—

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 →

323 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-96567.

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-2026-96567

Casky has 323 skills that investigate the attack patterns behind CVE-2026-96567. Run one and get CVSS-scored findings in 3 minutes.

Run the skill that detects this →

X Instagram LinkedIn