Vulnerability Description
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Author Name in all versions up to, and including, 2.10.3 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 Lazy Load Images feature of W3 Total Cache is enabled, as the unsafe re-emission occurs exclusively within the LazyLoad mutator's img tag rewriting step.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.2/UserExperi
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.2/UserExperi
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.2/UserExperi
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.2/UserExperi
- https://plugins.trac.wordpress.org/changeset/3635675/w3-total-cache/trunk/UserEx
- https://plugins.trac.wordpress.org/changeset?old_path=%2Fw3-total-cache/tags/2.1
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3635675%40w3-total-ca
- https://www.wordfence.com/threat-intel/vulnerabilities/id/16ac73ae-6a0a-4c9b-883
FAQ
What is CVE-2026-18109?
CVE-2026-18109 is a vulnerability with a CVSS score of 7.2 (HIGH). The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Author Name in all versions up to, and including, 2.10.3 due to insufficient input sanitization and out...
How severe is CVE-2026-18109?
CVE-2026-18109 has been rated HIGH with a CVSS base score of 7.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-18109?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.