CVE-2026-109220: Insecure Deserialization (CVSS 9.8)

Description

The PDF Invoice for WooCommerce + Drag and Drop Template Builder plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 7.1.1 via the 'customer_note' parameter parameter. This is due to insufficient sanitization of the customer_note checkout field, which is inlined verbatim into invoice HTML, entity-decoded back into a live tag by simplehtmldom, reassembled into raw bytes by mPDF, and passed to unserialize() in _getObjAttr without validation. This makes it possible for unauthenticated attackers to execute code on the server. An unauthenticated attacker can trigger the vulnerable code path on a default install by placing an anonymous WooCommerce checkout via the public Store API (POST /wc/store/v1/checkout) using a Direct Bank Transfer or cheque payment method, which automatically transitions the order to 'on-hold' status and fires the plugin's invoice-generation hook.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0052

Probability of exploitation

0.45%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-502 Deserialization of Untrusted Data

References

Other References

https://downloads.wordpress.org/plugin/pdf-for-woocommerce.7.2.0.zip https://plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/frontend/index.php#L378 https://plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/libs/HtmlDocument.php#L300 https://plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/libs/HtmlNode.php#L1266 https://plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/vendor/mpdf/mpdf/src/Mpdf.php#L9105 https://plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/woocommerce/emails/index.php#L70 https://plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/woocommerce/shortcodes.php#L708 https://www.wordfence.com/threat-intel/vulnerabilities/id/1bc3529c-6161-4b89-8a35-c3a9b7b8c308?source=cve

Frequently Asked Questions

What is CVE-2026-109220? +

The PDF Invoice for WooCommerce + Drag and Drop Template Builder plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 7.1.1 via the 'customer_note' parameter parameter. This is due to insufficient sanitization of the customer_note checkout field, which is inlined verbatim into invoice HTML, entity-decoded back into a live tag by simplehtmldom, reassembled into raw bytes by mPDF, and passed to unserialize() in _getObjAttr without validation. This makes it possible for unauthenticated attackers to execute code on the server. An unauthenticated attacker can trigger the vulnerable code path on a default install by placing an anonymous WooCommerce checkout via the public Store API (POST /wc/store/v1/checkout) using a Direct Bank Transfer or cheque payment method, which automatically transitions the order to 'on-hold' status and fires the plugin's invoice-generation hook. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-109220? +

CVE-2026-109220 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0052, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-109220? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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