CVE-2026-104010: Insecure Deserialization (CVSS 7.5)

Description

The WPSyncSheets For Contact Form 7 – CF7 Google Sheets Connector & Save to Database plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 1.8.0 via the 'any non-system CF7 field (e.g., your-message)' parameter parameter. This is due to insufficient sanitization of CF7 submission field values before database storage and the absence of an allowed_classes restriction on maybe_unserialize() during admin retrieval. This makes it possible for unauthenticated attackers to execute code on the server. Successful exploitation of the remote code execution gadget chain requires that a Google Sheets access token be configured in the plugin (its primary advertised feature), as this triggers autoloading of the bundled Monolog 2.10.0 library whose classes form the exploitable gadget chain; however, the underlying PHP Object Injection occurs regardless.

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CVSS v3.1 Score

7.5

HIGH

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

EPSS — Exploit Prediction

0.0058

Probability of exploitation

0.48%

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://plugins.trac.wordpress.org/browser/contactsheets-lite/tags/1.8.0/includes/class-wpsslc-google-api-functions.php#L157 https://plugins.trac.wordpress.org/browser/contactsheets-lite/tags/1.8.0/includes/class-wpsslc-service.php#L114 https://plugins.trac.wordpress.org/browser/contactsheets-lite/tags/1.8.0/includes/class-wpsslc-service.php#L184 https://plugins.trac.wordpress.org/browser/contactsheets-lite/tags/1.8.0/includes/entry/class-wpsslc-cf7-entries-table.php#L459 https://plugins.trac.wordpress.org/browser/contactsheets-lite/tags/1.8.0/includes/entry/class-wpsslc-single-entry.php#L131 https://plugins.trac.wordpress.org/changeset/3783292/contactsheets-lite/trunk/includes/entry/class-wpsslc-cf7-entries-table.php https://www.wordfence.com/threat-intel/vulnerabilities/id/366e20df-4cb2-4ba1-93fd-11552faa1a32?source=cve

Frequently Asked Questions

What is CVE-2026-104010? +

The WPSyncSheets For Contact Form 7 – CF7 Google Sheets Connector & Save to Database plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 1.8.0 via the 'any non-system CF7 field (e.g., your-message)' parameter parameter. This is due to insufficient sanitization of CF7 submission field values before database storage and the absence of an allowed_classes restriction on maybe_unserialize() during admin retrieval. This makes it possible for unauthenticated attackers to execute code on the server. Successful exploitation of the remote code execution gadget chain requires that a Google Sheets access token be configured in the plugin (its primary advertised feature), as this triggers autoloading of the bundled Monolog 2.10.0 library whose classes form the exploitable gadget chain; however, the underlying PHP Object Injection occurs regardless. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-104010? +

CVE-2026-104010 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0058, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-104010? +

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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