XSS in Automatic.css

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.0% 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-2026-15273: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-15273?
CVE-2026-15273 is a medium-severity vulnerability in Automatic.css, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-09-26.
How severe is CVE-2026-15273?
Medium severity. CVSS v3 base score is 6.4 out of 10.