CVE-2026-15273: XSS (CVSS 6.4)

Description

The Automatic.css plugin for WordPress is vulnerable to Stored Cross-Site Scripting via REQUEST_URI in all version 4.0.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that will execute whenever an administrator accesses the Activity Log settings page.

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CVSS v3.1 Score

6.4

MEDIUM

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

EPSS — Exploit Prediction

0.0022

Probability of exploitation

0.11%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://automaticcss.com/changelogs/ https://plugins.trac.wordpress.org/browser/automaticcss-plugin/trunk/classes/Helpers/Logger.php#L187 https://plugins.trac.wordpress.org/browser/automaticcss-plugin/trunk/classes/Lib/WideEvents/Formatter/JsonFormatter.php#L25 https://plugins.trac.wordpress.org/browser/automaticcss-plugin/trunk/classes/Plugin.php#L175 https://plugins.trac.wordpress.org/browser/automaticcss-plugin/trunk/classes/UI/Settings_Page/Activity_Log.php#L90 https://www.wordfence.com/threat-intel/vulnerabilities/id/07d697c5-1c15-4d3a-8637-cc4fd408f209?source=cve

Frequently Asked Questions

What is CVE-2026-15273? +

The Automatic.css plugin for WordPress is vulnerable to Stored Cross-Site Scripting via REQUEST_URI in all version 4.0.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that will execute whenever an administrator accesses the Activity Log settings page. It has a CVSS v3.1 base score of 6.4 (MEDIUM).

How severe is CVE-2026-15273? +

CVE-2026-15273 has a CVSS v3.1 score of 6.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0022, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-15273? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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