Perfmatters Plugin up to 2.5.9.1 on WordPress PMCS::action_handler delete path traversal

Summaryinfo

A vulnerability classified as critical has been found in Perfmatters Plugin up to 2.5.9.1 on WordPress. Affected by this issue is the function PMCS::action_handler. This manipulation of the argument delete causes path traversal. This vulnerability is handled as CVE-2026-4350. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability has been found in Perfmatters Plugin up to 2.5.9.1 on WordPress and classified as critical. Affected by this vulnerability is the function PMCS::action_handler. The manipulation of the argument delete with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. As an impact it is known to affect integrity, and availability. The summary by CVE is:

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.

The weakness was released by Phú. The advisory is shared at wordfence.com. This vulnerability is known as CVE-2026-4350 since 03/17/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/03/2026). MITRE ATT&CK project uses the attack technique T1006 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-18609). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• WordPress Plugin

Name

• Perfmatters Plugin

Version

• 2.5.9.0
• 2.5.9.1

CPE 2.3info

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• 🔒

CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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