What’s Vulnerable › Vulnerabilities

CVE-2026-15273: Automatic.css 4.0.0 - Unauthenticated Stored Cross-Site Scripting via REQUEST_URI

• Severity: medium (CVSS 6.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-26 · updated 2026-09-28
• Weakness: CWE-79

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.

Affected products

• Automatic.css: 4.0.0

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

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