CVE-2026-18109: boldgrid w3_total_cache Cross-site Scripting
Vulnerability summary
CVE-2026-18109 is a high (CVSS 7.2) Cross-site Scripting vulnerability in boldgrid w3_total_cache. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.9% of scored vulnerabilities.
Timeline
- 14-08-2026PublishedVulnerability first disclosed.
- 14-08-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 3 sources · 1 version- NVDNIST7.2HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- wordfenceSource7.2HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS trend
Probability
0.43%
Chance of exploitation in the next 30 days
Percentile
36%
Versus all other CVEs
30-day change
+0.16 pp
From 0.27% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Boldgrid1 product
- w3_total_cache≤ 2.10.3
Wordpress1 product
- w3-total-cache≤ 2.10.3 (fixed in 2.10.4)
2 vendors · 2 products