CVE-2026-3604: WP SEO Structured Data Schema · Cross-site Scripting
Affects WP SEO Structured Data SchemaSource CVE Database V5
Not known to be exploited · CVSS 4.9 Medium.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 12 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| kcseoproWP SEO Structured Data Schema | Affected
| Fixed in– |
AI-suggested
Until an official fix is released, limit Contributor-level access to trusted users only and consider monitoring or restricting use of the _kcseo_ative_tab parameter if possible. Avoid exposing pages that could contain injected scripts to untrusted users. Follow updates from the plugin vendor for an official patch or mitigation instructions.
Description
The WP SEO Structured Data Schema WordPress plugin versions up to and including 2.8.1 contain a stored cross-site scripting (XSS) vulnerability via the _kcseo_ative_tab parameter. This vulnerability arises from insufficient input sanitization and output escaping, allowing authenticated users with Contributor-level access or higher to inject malicious scripts. These scripts execute when other users view the affected pages. The vulnerability has a medium severity with a CVSS score of 4.9. No official patch or remediation guidance has been provided yet, and no known exploits are reported in the wild.
References
- wordfence.com/threat-intel/vulnerabilities/id/315fbc93-5af3-4fe9-b97a-a09957e54c97?source=cve (opens in a new tab)
- plugins.trac.wordpress.org/browser/wp-seo-structured-data-schema/trunk/lib/classes/KcSeoMetaData.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/wp-seo-structured-data-schema/tags/2.8.1/lib/classes/KcSeoMetaData.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/wp-seo-structured-data-schema/trunk/lib/classes/KcSeoMetaData.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/wp-seo-structured-data-schema/tags/2.8.1/lib/classes/KcSeoMetaData.php (opens in a new tab)