CVE-2026-18109 json
W3 Total Cache <= 2.10.3 - Unauthenticated Stored Cross-Site Scripting via Comment Author Name
published 2026-08-14 2 mo ago modified 2026-08-14 2 mo ago also EUVD-2026-58570
- cvss
- 7.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 37%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
Affected products
- boldgrid W3 Total Cache
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/16ac73ae-6a0a-4c9b-8830-e0745061e587?source=cve
- plugins.trac.wordpress.org /browser/w3-total-cache/tags/2.10.2/UserExperience_LazyLoad_Mutator.php#L162
- plugins.trac.wordpress.org /browser/w3-total-cache/tags/2.10.2/UserExperience_LazyLoad_Mutator.php#L85
- plugins.trac.wordpress.org /browser/w3-total-cache/tags/2.10.2/UserExperience_LazyLoad_Plugin.php#L116
- plugins.trac.wordpress.org /browser/w3-total-cache/tags/2.10.2/UserExperience_LazyLoad_Mutator.php#L403
- plugins.trac.wordpress.org /changeset?reponame=&new=3635675%40w3-total-cache%2Ftags%2F2.10.4&old=3625062%40w3-total-cache%2Ftags%2F2.10.3
- plugins.trac.wordpress.org /changeset/3635675/w3-total-cache/trunk/UserExperience_LazyLoad_Mutator.php
- plugins.trac.wordpress.org /changeset?old_path=%2Fw3-total-cache/tags/2.10.3&new_path=%2Fw3-total-cache/tags/2.10.4
Sources
- CVE List CVE-2026-18109
- NVD CVE-2026-18109
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.