CVE-2026-87920
Received Received - Intake

Stored XSS in W3 Total Cache WordPress Plugin

Publication date: 2026-10-02

Last updated on: 2026-10-02

Assigner: Wordfence

Description
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via Output-Buffer Regex Rewrite in all versions up to, and including, 2.10.6 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. This vulnerability is only exploitable when the 'Remove query strings from static resources' option is enabled in W3 Total Cache, as mutate_url() must strip the '?' delimiter and everything following it — including the closing quote of the outer attribute — to break the attribute boundary.

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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-2026-87920
EUVD
EUVD-2026-91335

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
wordpress w3_total_cache to 2.10.6 (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 is a Stored Cross-Site Scripting (XSS) vulnerability in the W3 Total Cache WordPress plugin. It allows unauthenticated attackers to inject malicious scripts into web pages by exploiting insufficient input sanitization and output escaping in comment content. The attack requires the 'Remove query strings from static resources' option to be enabled in the plugin.

Detection Guidance

Check if the W3 Total Cache plugin is installed and its version is up to 2.10.6. Inspect WordPress pages for unexpected scripts in comment sections. Review the 'Remove query strings from static resources' setting in W3 Total Cache.

Impact Analysis

An attacker could inject scripts that execute when users visit affected pages, potentially stealing cookies, session tokens, or other sensitive data. This could lead to account takeovers, defacement of websites, or spreading malware to visitors.

Compliance Impact

This vulnerability could lead to data breaches, which may violate GDPR (data protection) and HIPAA (health information privacy) requirements. Organizations could face fines or legal penalties for failing to protect user data from such exploits.

Mitigation Strategies

Update the W3 Total Cache plugin to the latest version. Disable the 'Remove query strings from static resources' option. Review and remove any suspicious scripts from comments or pages.

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