Vulnerability intelligence
CVE-2026-18051
The W3 Total Cache WordPress plugin before 2.10.5 does not properly validate the request path it uses to build cache file names, allowing unauthenticated attackers to write a file into any existing directory on the server, inside or outside the web root, overwriting whatever occupies the target name. On Apache, the same flaw overwrites the site's .htaccess files, which breaks the site and can strip hardening rules that other security measures rely on.
CVSS Score
10
Critical
EPSS — Exploit Probability
0.6%
Riskier than 45% of all CVEs · checked 2026-10-03
Exploitation
Not in CISA KEV
KEV does not include every exploited vulnerability
Remediation
unknown
Check vendor advisories
1 article across 1 outlet · first covered Aug 19, 2026 · latest Aug 19, 2026
Coverage timeline
-
CVE-2026-18051 (CVSS 10): Unauthenticated Arbitrary File Write Hits 900k W3 Total Cache Sitessecurityonline.info · Aug 19, 2026