Vulnerability Description
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via LazyLoad Background Mutator in all versions up to, and including, 2.10.5 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 requires the "Lazy Load Images" feature with "Process background images" to be enabled, and the malicious comment to be approved by a moderator before execution is triggered.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperi
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperi
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperi
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperi
- https://plugins.trac.wordpress.org/changeset/3680101/w3-total-cache/tags/2.10.6/
- https://plugins.trac.wordpress.org/changeset?old_path=%2Fw3-total-cache/tags/2.1
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3680101%40w3-total-ca
- https://www.wordfence.com/threat-intel/vulnerabilities/id/5580ad05-af50-4899-9cb
FAQ
What is CVE-2026-78438?
CVE-2026-78438 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 Content via LazyLoad Background Mutator in all versions up to, and including, 2.10.5 due to insufficien...
How severe is CVE-2026-78438?
CVE-2026-78438 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-2026-78438?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.