CVE-2026-4350

Perfmatters <= 2.5.9.1 - Authenticated (Subscriber+) Arbitrary File Deletion via 'delete' Parameter

2026-04-02 19:02
h0xilo

Strategic Overview

Status
Patched in 2.6.0
Affected Plugin
Perfmatters
Affected Version
<= 2.5.9.1
CVSS
8.1High
Weakness type
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE
CVE-2026-4350
View all Perfmatters vulnerabilities

At a glance

CVE-2026-4350 is a high-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the Perfmatters WordPress plugin, affecting versions <= 2.5.9.1. It carries a CVSS score of 8.1 (reachable over the network; low attack complexity; high integrity, availability impact). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 2.6.0; sites on affected versions should update now. Disclosed April 2026, reported by h0xilo.

Vulnerability Overview

The Perfmatters plugin for WordPress is vulnerable to arbitrary file deletion via path traversal in all versions up to, and including, 2.5.9.1. This is due to the `PMCS::action_handler()` method processing the `$_GET['delete']` parameter without any sanitization, authorization check, or nonce verification. The unsanitized filename is concatenated with the storage directory path and passed to `unlink()`. This makes it possible for authenticated attackers, with Subscriber-level access and above, to delete arbitrary files on the server by using `../` path traversal sequences, including `wp-config.php` which would force WordPress into the installation wizard and allow full site takeover.

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 interaction from a victim user. A successful exploit has high impact on integrity, availability.

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

Perfmatters <= 2.5.9.1 carries this weakness at delete, and reaching it takes an account at Subscriber level or above. 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 Perfmatters the fix is 2.6.0: builds <= 2.5.9.1 are affected, anything from 2.6.0 onward is not.

Remediation

Update to version 2.6.0, or a newer patched version

How does WordSec protect against this?

An attacker needs Subscriber access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Perfmatters 2.6.0 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-4350https://www.wordfence.com/threat-intel/vulnerabilities/id/58b9dab8-8539-4b53-b08d-f6ee3e1e744chttps://nvd.nist.gov/vuln/detail/CVE-2026-4350

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C