WordPress security changelog
CRITICAL CVE-2026-18051 Deferred

W3 Total Cache request paths permit unauthenticated arbitrary file overwrite

W3 Total Cache before 2.10.5 does not validate the request path used to construct cache-file names. An unauthenticated attacker can write into any existing server directory and overwrite the target name; on Apache the flaw can overwrite .htaccess, break the site and remove hardening rules.

CVE / CNA score 10.0 CVSS 3.1 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD score Pending NVD has not published its own CVSS assessment.
Component
W3 Total Cache
Plugin slug
w3-total-cache
Affected
< 2.10.5
Safe version
2.10.5
Published
Aug 19, 2026
Weakness
CWE-22 — Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

This CVE was published Aug 19, 2026 and is one of 23 known issues for this plugin.

Update, patch or deactivate.

Update W3 Total Cache to 2.10.5 or later. Restore overwritten files from known-good copies, review .htaccess and investigate the site if exploitation is suspected.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Technical description

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.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H

Primary and upstream sources