CVE-2026-3427: Yoast Seo – Advanced Seo With Real-Time Guidance And Built-In Ai

Medium severity, CVSS 6.4. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Yoast Yoast Seo – Advanced Seo With Real-Time Guidance And Built-In Ai: up to and including 27.1.1

Published 2026-03-22. Last modified 2026-06-17.