Stored XSS in WooCommerce PDF Invoice Plugin

The PDF Invoices & Packing Slips for WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'billing_address.first_name / last_name / company, customer_note' parameter in all versions up to, and including, 5.16.4 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. This is an incomplete fix for CVE-2026-92244: the wp_kses() allow-list introduced in 5.16.2 correctly blocks raw-tag payloads but is bypassed by entity-encoded payloads (e.g., <img onerror=…>) that contain no literal angle-bracket characters and are therefore passed through unmodified before the trailing decode rematerializes them.

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

This vulnerability is a Stored Cross-Site Scripting (XSS) flaw in the PDF Invoices & Packing Slips for WooCommerce plugin affecting versions up to 5.16.4. Attackers can inject malicious JavaScript through customer-facing fields like billing address names, company names, and customer notes. Since the injected scripts persist in the database, any user accessing the affected pages—including administrators and customers—will execute the attacker's code without authentication required. This is particularly dangerous for WooCommerce stores as it compromises the integrity of financial records, customer data, and site administration, potentially leading to credential theft, malware distribution, or unauthorized transactions.

Casky's 323 mapped security skills detect this attack pattern by analyzing both the Initial Access (TA0001) and Reconnaissance (TA0043) phases where attackers probe for and exploit insufficient input validation. Practitioners using Casky with Claude's extended reasoning capabilities would identify the attack chain through detection of: unsanitized input flowing from customer form fields into stored database records, absence of output encoding when rendering invoice/packing slip templates, and malicious script payloads in HTML contexts. The platform's skill mapping would flag CWE-79 violations, correlate them with common WooCommerce parameter injection points (billing_address fields, customer_note), and surface that this represents an incomplete patch of CVE-2026-92—signaling attackers may attempt bypass techniques. Security teams would see findings highlighting the need for comprehensive input sanitization and context-aware output escaping across all customer-submitted fields.

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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 →

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-2026-107750.

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-2026-107750

Casky has 323 skills that investigate the attack patterns behind CVE-2026-107750. Run one and get CVSS-scored findings in 3 minutes.

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