CVE-2026-3427
Yoast SEO <= 27.1.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'jsonText' Block Attribute
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Yoast SEO <= 27.1.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'jsonText' Block Attribute
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.
- Record
CVE-2026-3427- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-14273
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.
- Record
EUVD-2026-14273- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-84j4-wrx9-vrgx
The Yoast SEO – Advanced SEO with real-time guidance and built-in AI plugin for WordPress is...
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.
- Record
GHSA-84j4-wrx9-vrgx- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-3427- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
Yoast SEO <= 27.1.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'jsonText' Block Attribute
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.
- Record
CVE-2026-3427- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-3427 is a medium vulnerability (CVSS 6.4) in Yoast Seo – Advanced Seo With Real-time Guidance And Built-in Ai, published March 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.20%, the 10th percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/fee1fef5-5716-49e0-a04e-d0dae527fcfc?source=cve
plugins.trac.wordpress.org/browser/wordpress-seo/tags/27.0/src/generators/schema/howto.php
github.com/Yoast/wordpress-seo/pull/23035
nvd.nist.gov/vuln/detail/CVE-2026-3427