Path Traversal in W3 Total Cache

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (45.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-18051: held from 0.004 to 0.006.

EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.001

Affected products

  • W3 Total Cache

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18051?
CVE-2026-18051 is a critical-severity vulnerability in W3 Total Cache, classified under Path Traversal. CVSS score: 10.0/10. Published 2026-08-19.
How severe is CVE-2026-18051?
Critical severity. CVSS v3 base score is 10.0 out of 10.