High severity7.2NVD Advisory· Published Sep 5, 2026· Updated Sep 8, 2026
CVE-2026-78438
CVE-2026-78438
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
1- Range: <=2.10.5
Patches
Vulnerability mechanics
References
8- plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperience_LazyLoad_Mutator.phpnvd
- plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperience_LazyLoad_Mutator.phpnvd
- plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperience_LazyLoad_Mutator.phpnvd
- plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperience_LazyLoad_Plugin.phpnvd
- plugins.trac.wordpress.org/changeset/3680101/w3-total-cache/tags/2.10.6/UserExperience_LazyLoad_Mutator.phpnvd
- plugins.trac.wordpress.org/changesetnvd
- plugins.trac.wordpress.org/changesetnvd
- www.wordfence.com/threat-intel/vulnerabilities/id/5580ad05-af50-4899-9cbf-39ad8000eb6anvd
News mentions
1- Wordfence Intelligence Weekly WordPress Vulnerability Report (August 31, 2026 to September 6, 2026)Wordfence Blog · Sep 10, 2026