CVE-2026-3427
Yoast SEO <= 27.1.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'jsonText' Block Attribute
- State
- Published
- Severity
- 6.4 Medium
- Published
- Mar 22, 2026
- Updated
- Apr 8, 2026
- Reserved
- Mar 2, 2026
Description
The Yoast SEO – Advanced SEO with real-time guidance and built-in AI plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the the `jsonText` block attribute in all versions up to, and including, 27.1.1 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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.4 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N | Wordfence |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
Yoast SEO – Advanced SEO with real-time guidance and built-in AIyoast |
|
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/fee1fef5-5716-49e0-a04e-d0dae527fcfc?source=cve
- https://plugins.trac.wordpress.org/browser/wordpress-seo/tags/27.0/src/generators/schema/howto.php#L125
- https://plugins.trac.wordpress.org/browser/wordpress-seo/tags/27.0/inc/class-wpseo-utils.php#L915
- https://github.com/Yoast/wordpress-seo/pull/23035
- https://plugins.trac.wordpress.org/changeset/3475308/wordpress-seo
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