CVE-2026-18051

W3 Total Cache < 2.10.5 - Unauthenticated Path Traversal

2026-08-21 00:00
Jakub Herman

Strategic Overview

Status
Patched in 2.10.5
Affected Plugin
W3 Total Cache
Affected Version
< 2.10.5
CVSS
7.5High
Weakness type
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE
CVE-2026-18051
View all W3 Total Cache vulnerabilities

At a glance

CVE-2026-18051 is a high-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the W3 Total Cache WordPress plugin, affecting versions < 2.10.5. It carries a CVSS score of 7.5 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires no authentication. The issue is fixed in version 2.10.5; sites on affected versions should update now. Disclosed August 2026, reported by Jakub Herman.

Vulnerability Overview

The W3 Total Cache plugin for WordPress is vulnerable to Path Traversal in all versions up to 2.10.5. This is due to insufficient validation of a user supplied path. This makes it possible for unauthenticated attackers to access files and directories outside of the intended directory.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Reaching this weakness in W3 Total Cache < 2.10.5 takes no account at all. Path traversal happens when user-controlled text is used to build a filesystem path without being constrained to an intended directory, so sequences like ../ walk the resolved path somewhere else.

Depending on the operation, it means reading files outside the intended folder — wp-config.php being the usual target — or writing to and deleting paths the web server can touch. For W3 Total Cache the fix is 2.10.5: builds < 2.10.5 are affected, anything from 2.10.5 onward is not.

Remediation

Update to version 2.10.5, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: W3 Total Cache 2.10.5 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-18051https://www.wordfence.com/threat-intel/vulnerabilities/id/c9586c39-3018-449f-8e03-3c5920438092https://nvd.nist.gov/vuln/detail/CVE-2026-18051

Related records

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