CVE-2026-18109
W3 Total Cache <= 2.10.3 - Unauthenticated Stored Cross-Site Scripting via Comment Author Name
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.
INFO
Published Date :
Aug. 14, 2026, 3:16 a.m.
Last Modified :
Aug. 14, 2026, 3:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update the W3 Total Cache plugin to the latest version.
- Ensure the Lazy Load Images feature is configured securely.
- Sanitize all user-supplied comment author names.
- Escape output for comment author names.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-18109.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-18109 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-18109
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-18109 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-18109 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Aug. 14, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'boldgrid', 'product': 'W3 Total Cache', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.10.3'}], 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.2/UserExperience_LazyLoad_Mutator.php#L162 Added Reference https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.2/UserExperience_LazyLoad_Mutator.php#L403 Added Reference https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.2/UserExperience_LazyLoad_Mutator.php#L85 Added Reference https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.2/UserExperience_LazyLoad_Plugin.php#L116 Added Reference https://plugins.trac.wordpress.org/changeset/3635675/w3-total-cache/trunk/UserExperience_LazyLoad_Mutator.php Added Reference https://plugins.trac.wordpress.org/changeset?old_path=%2Fw3-total-cache/tags/2.10.3&new_path=%2Fw3-total-cache/tags/2.10.4 Added Reference https://plugins.trac.wordpress.org/changeset?reponame=&new=3635675%40w3-total-cache%2Ftags%2F2.10.4&old=3625062%40w3-total-cache%2Ftags%2F2.10.3 Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/16ac73ae-6a0a-4c9b-8830-e0745061e587?source=cve