Stored XSS in CorvusPay WooCommerce Payment Gateway Plugin

The CorvusPay WooCommerce Payment Gateway plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'approval_code' parameter in all versions up to, and including, 2.7.4 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 unauthenticated REST endpoint POST /wp-json/corvuspay/success/ is registered with permission_callback set to __return_true, and although a signature validation step exists it only logs the result without halting execution, meaning an attacker can supply a completely arbitrary signature and have a malicious approval_code stored in the database unchallenged.

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 CorvusPay WooCommerce Payment Gateway plugin contains a stored cross-site scripting (XSS) vulnerability in versions up to 2.7.4 that allows unauthenticated attackers to inject malicious scripts through the 'approval_code' parameter via an unprotected REST endpoint. Because the plugin fails to properly sanitize input and escape output, these injected scripts persist in the database and execute in the browsers of all users who access the affected pages—including administrators and customers. This impacts any WordPress installation using this payment processing plugin, creating a direct path for attackers to steal session tokens, capture payment data, or compromise user accounts without requiring authentication or admin privileges.

Casky's 322 mapped skills detect the attack patterns underlying this vulnerability by correlating MITRE ATT&CK techniques TA0001 (Reconnaissance) and TA0043 (Resource Development) with CWE-79 XSS signatures. Practitioners using Casky's Claude-powered analysis would observe detection patterns including: unauthenticated requests to REST endpoints with suspicious parameter payloads, script injection attempts in approval_code values, database queries containing script tags or event handlers, and page rendering anomalies indicating injected content execution. The platform's extended reasoning capabilities would flag the specific REST endpoint POST /wp-json/corvuspay/success/ as a critical attack surface, trace injection points back to insufficient output escaping in payment confirmation pages, and identify this as a pre-exploitation reconnaissance and infrastructure testing technique used before launching broader attacks against WooCommerce installations.

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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-2026-6939.

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

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