XSS in Eazyserver Sentence To Seo (Keywords, Description And Tags)

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (31.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-4142: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4142?
CVE-2026-4142 is a medium-severity vulnerability in Eazyserver Sentence To Seo (Keywords, Description And Tags), classified under Cross-site Scripting. CVSS score: 4.4/10. Published 2026-04-22.
How severe is CVE-2026-4142?
Medium severity. CVSS v3 base score is 4.4 out of 10.