CVE-2026-78471
Received Received - Intake

Stored XSS in Autoptimize WordPress Plugin

Publication date: 2026-10-02

Last updated on: 2026-10-02

Assigner: Wordfence

Description
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.

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Meta Information

Published
2026-10-02
Last Modified
2026-10-02
Generated
2026-10-02
AI Q&A
2026-10-02
EPSS Evaluated
N/A
NVD
CVE-2026-78471
EUVD
EUVD-2026-91179

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
autoptimize autoptimize to 3.1.15.1 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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Executive Summary

This vulnerability is a Stored Cross-Site Scripting (XSS) flaw in the Autoptimize WordPress plugin. It allows unauthenticated attackers to inject malicious scripts into web pages via the Comment Author Name field due to insufficient input sanitization and output escaping. The injected scripts execute when users access the affected pages.

Impact Analysis

An attacker could steal user session cookies, redirect users to malicious sites, or perform actions on their behalf. This requires specific conditions like an administrator enabling certain options, the presence of another plugin file, and manual approval of a malicious comment.

Compliance Impact

This vulnerability could lead to unauthorized access to user data, violating GDPR's data protection principles and HIPAA's security requirements. It may result in data breaches, unauthorized data exposure, and non-compliance with privacy regulations.

Mitigation Strategies

Update the Autoptimize plugin to the latest version beyond 3.1.15.1. Disable the 'Lazy-load images?' option if enabled. Remove or disable the w3-total-cache plugin if present. Review and moderate comments for suspicious content before approval.

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