What is CVE-2026-78471?

CVE-2026-78471 is a medium-severity vulnerability in Optimizingmatters Autoptimize, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-10-02.

How severe is CVE-2026-78471?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Optimizingmatters Autoptimize

CVE-2026-78471

The Autoptimize plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Author Name in all versions up to, and including, 3.1.15.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires an administrator to have enabled Autoptimize's 'Lazy-load images?' option, the w3-total-cache/w3-total-cache.php file to be present on disk with the plugin disabled, a class named Minify_HTML to be loaded into scope by another plugin, and the malicious comment to be approved by a moderator before the payload renders.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-10-02 · last modified 2026-10-02.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Optimizingmatters Autoptimize

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-78471?: CVE-2026-78471 is a medium-severity vulnerability in Optimizingmatters Autoptimize, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-10-02.
How severe is CVE-2026-78471?: Medium severity. CVSS v3 base score is 5.4 out of 10.