# CVE-2026-15273: Automatic.css plugin Stored Cross-Site Scripting via REQUEST_URI

Source: https://junglewise.ai/threats/cve-2026-15273-the-automatic-css-plugin-for-wordpress-is-vulnerable-to-stored  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-26. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-15273 · Severity: medium · CVSS 6.4 · Published 2026-09-26

The Automatic.css WordPress plugin, which provides a design system and CSS framework for WordPress sites, contains a vulnerability that allows unauthenticated attackers to inject malicious scripts. When an administrator views the Activity Log settings page, the injected scripts execute in their browser, potentially allowing attackers to steal admin credentials, modify site content, or take over the website.

Vendors: [Automatic](https://junglewise.ai/threats/vendors/automatic).

## Quick answers

**Is CVE-2026-15273 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-15273 being exploited in the wild.

**How severe is CVE-2026-15273?** Medium severity, with a CVSS score of 6.4, published 26 September 2026.

**Which products and versions are affected?** Automatic.css plugin 4.0.0.

**Is there a fix for CVE-2026-15273?** A patch was published on 2026-08-13: Fixed in version 4.0.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-15273 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-15273?** Check whether you run Automatic.css plugin at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A Stored Cross-Site Scripting (XSS) vulnerability in Automatic.css version 4.0.0 exists due to insufficient input sanitization and output escaping of the REQUEST_URI parameter, which is logged and displayed on the Activity Log settings page. An unauthenticated attacker can inject arbitrary JavaScript by crafting a malicious URL; the payload persists in the activity log and executes whenever an administrator accesses the settings page. A patch was released in version 4.0.1 on August 13, 2026.

## Affected products

- Automatic Automatic.css plugin 4.0.0

## Timeline

- 2026-09-26: disclosed: CVE-2026-15273 published on NVD
- 2026-08-13: patched: Fixed in version 4.0.1

## References

- [https://automaticcss.com/changelogs/](https://automaticcss.com/changelogs/)
- [https://plugins.trac.wordpress.org/browser/automaticcss-plugin/trunk/classes/Helpers/Logger.php](https://plugins.trac.wordpress.org/browser/automaticcss-plugin/trunk/classes/Helpers/Logger.php)