CVE-2026-87920

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.

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/34bd7c32-f4c5-4015-909a-e4730f35494b?source=cve

https://plugins.trac.wordpress.org/changeset?reponame=&new=3723494%40w3-total-cache%2Ftags%2F2.10.7&old=3681561%40w3-total-cache%2Ftags%2F2.10.6

https://plugins.trac.wordpress.org/changeset/3723494/w3-total-cache/trunk/BrowserCache_Plugin.php

https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.6/BrowserCache_Plugin.php#L336

https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.6/BrowserCache_Plugin.php#L259

https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.6/BrowserCache_Plugin.php#L208

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-91335

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

EPSS