CVE-2026-4142: The Sentence To SEO (keywords, description and tags) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Permanent keywords' fi...

Description

The Sentence To SEO (keywords, description and tags) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Permanent keywords' field in all versions up to and including 1.0. This is due to insufficient input sanitization and output escaping. The plugin reads user input via filter_input_array(INPUT_POST) which applies no HTML sanitization (FILTER_DEFAULT), stores it unsanitized to the WordPress options table via update_option(), and then outputs the stored value directly into a textarea element without any escaping using PHP short echo tags (<?= ?>). An attacker can break out of the textarea element using a closing </textarea> tag and inject arbitrary HTML/JavaScript. This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses the plugin's settings page.

Metrics

CVSS 3.1

4.4/10

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N

EPSS Probability

0.33%

24.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Apr 22, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-4142?

The Sentence To SEO (keywords, description and tags) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'Permanent keywords' field in all versions up to and including 1.0. This is due to insufficient input sanitization and output escaping. The plugin reads user input via filter_input_array(INPUT_POST) which applies no HTML sanitization (FILTER_DEFAULT), stores it unsanitized to the WordPress options table via update_option(), and then outputs the stored value directly into a textarea element without any escaping using PHP short echo tags (<?= ?>). An attacker can break out of the textarea element using a closing </textarea> tag and inject arbitrary HTML/JavaScript. This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses the plugin's settings page.

How severe is CVE-2026-4142?

CVE-2026-4142 has a CVSS score of 4.4/10 (MEDIUM severity). The EPSS model estimates a 0.33% probability of exploitation in the next 30 days.

How do I fix CVE-2026-4142?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.