WP SEO Structured Data Schema <= 2.8.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via '_kcseo_ative_tab' Parameter
Strategic Overview
- Status
- Unpatched
- Affected Plugin
- WP SEO Structured Data Schema
- Affected Version
<= 2.8.1- CVSS
- 4.9Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2026-3604
At a glance
CVE-2026-3604 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the WP SEO Structured Data Schema WordPress plugin, affecting versions <= 2.8.1. It carries a CVSS score of 4.9 (reachable over the network). Exploitation requires an authenticated account at Contributor level or above. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed May 2026, reported by Muhammad Yudha - DJ.
Vulnerability Overview
The WP SEO Structured Data Schema plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `_kcseo_ative_tab` parameter in all versions up to, and including, 2.8.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Reaching this weakness in WP SEO Structured Data Schema <= 2.8.1 takes an account at Contributor level or above. 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. No fixed build of this plugin is recorded for WP SEO Structured Data Schema yet, so installs running <= 2.8.1 stay exposed until the vendor ships one.
Remediation
No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.
How does WordSec protect against this?
An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.
- Firewall
- Alerts
External References
Related records
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