CVE-2026-13251

Perfmatters <= 2.6.4 - Unauthenticated Arbitrary File Read via 's' Parameter

2026-07-01 21:08

Strategic Overview

Status: Patched in 2.6.5
Affected Plugin: Perfmatters
Affected Version: <= 2.6.4
CVSS: 7.5High
Weakness type: CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE: CVE-2026-13251

At a glance

CVE-2026-13251 is a high-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the Perfmatters WordPress plugin, affecting versions <= 2.6.4. 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 2.6.5; sites on affected versions should update now. Disclosed July 2026, reported by daroo.

Vulnerability Overview

The Perfmatters plugin for WordPress is vulnerable to Directory Traversal in all versions up to, and including, 2.6.4 via the 's' parameter. This makes it possible for unauthenticated attackers to read the contents of arbitrary files on the server, which can contain sensitive information. Exploitation requires the Local Google Fonts feature to be enabled (disabled by default), pretty permalinks to be active, and RSS feed links to remain enabled in the plugin settings.

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 Perfmatters <= 2.6.4 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 Perfmatters the fix is 2.6.5: builds <= 2.6.4 are affected, anything from 2.6.5 onward is not.

Remediation

Update to version 2.6.5, 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: Perfmatters 2.6.5 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-2026-13251 https://www.wordfence.com/threat-intel/vulnerabilities/id/2c0082ff-2a33-44e9-b0d0-8b9a404ab648 https://nvd.nist.gov/vuln/detail/CVE-2026-13251

Related records

Same weakness class

Other vulnerabilities in Perfmatters

CVSS Vector

7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityNone
AvailabilityNone

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