CVE-2026-96752

Zero Spam for WordPress <= 5.7.10 - Unauthenticated Stored Cross-Site Scripting via Nested POST Array Keys via Contact Form 7 Integration

2026-09-24 19:10
Adrien Brunner

Strategic Overview

Status
Patched in 5.7.11
Affected Plugin
Zero Spam for WordPress
Affected Version
<= 5.7.10
CVSS
7.2High
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-96752
View all Zero Spam for WordPress vulnerabilities

At a glance

CVE-2026-96752 is a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Zero Spam for WordPress WordPress plugin, affecting versions <= 5.7.10. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 5.7.11; sites on affected versions should update now. Disclosed September 2026, reported by Adrien Brunner.

Vulnerability Overview

The Zero Spam for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Nested POST Array Keys via Contact Form 7 Integration in all versions up to, and including, 5.7.10 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 payload is delivered by submitting a Contact Form 7 request with a nested POST array key containing arbitrary HTML or JavaScript — PHP parses the field name into a nested array key, which is stored verbatim in the zerospam_log.submission_data column when Zero Spam flags the submission as spam due to the absence of the zerospam_david_walsh_key field.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in Zero Spam for WordPress <= 5.7.10 takes no account at all. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Zero Spam for WordPress the fix is 5.7.11: builds <= 5.7.10 are affected, anything from 5.7.11 onward is not.

Remediation

Update to version 5.7.11, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Zero Spam for WordPress 5.7.11 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-96752https://www.wordfence.com/threat-intel/vulnerabilities/id/01540d78-ae46-4556-9a7f-3f8b8dbbcbd7https://nvd.nist.gov/vuln/detail/CVE-2026-96752

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C