PDF Invoice for WooCommerce + Drag and Drop…: Deserialization of Untrusted Data
CVE-2026-109220 is a critical-severity deserialization of untrusted data vulnerability in PDF Invoice for WooCommerce + Drag and Drop Template Builder from Addonsorg, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected PDF Invoice for WooCommerce + Drag and Drop Template Builder versions: 7.1.1 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.52% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of PDF Invoice for WooCommerce + Drag and Drop Template Builder you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Addonsorg | PDF Invoice for WooCommerce + Drag and Drop Template Builder | 7.1.1 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (wordfence.com).
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
- downloads.wordpress.org/plugin/pdf-for-woocommerce.7.2.0.zip
- plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/frontend/index.php#L378
- plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/libs/HtmlDocument.php#L300
- plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/libs/HtmlNode.php#L1266
- plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/vendor/mpdf/mpdf/src/Mpdf.php#L9105
- plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/woocommerce/emails/index.php#L70
- plugins.trac.wordpress.org/browser/pdf-for-woocommerce/tags/7.1.1/woocommerce/shortcodes.php#L708
- wordfence.com/threat-intel/vulnerabilities/id/1bc3529c-6161-4b89-8a35-c3a9b7b8c308?source=cve
Recent Deserialization of Untrusted Data vulnerabilities
- 9.8 Critical severity
- 8.7 High severity
- 8.8 High severity
- 8.8 High severity
- 7.3 High severity
- 9.8 Critical severity
Spotted an error? Tell us.