CVE-2026-18109

High

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.

SeverityHigh
CVSS7.2
Exploit probability—
ProductW3 Total Cache
PublishedAug 14, 2026
First seenAug 14, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
boldgrid W3 Total Cachev ≤ 2.10.3—

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