# CVE-2026-13251: Perfmatters <= 2.6.4 - Unauthenticated Arbitrary File Read via 's' Parameter

> Unauthenticated attackers can read arbitrary server files via directory traversal in the Perfmatters WordPress plugin when specific features are enabled.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Jul 2026
- **Updated:** 2 Jul 2026
- **Also known as:** GHSA-8456-6w7p-xg3h

## What is CVE-2026-13251?

CVE-2026-13251 is a high-severity path traversal vulnerability in Perfmatters, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-13251?


## How do I fix CVE-2026-13251?

No fix has been published for CVE-2026-13251 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-13251 being exploited?

There is no known exploitation of CVE-2026-13251 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-13251 and fix it if it is affected.

What it is: CVE-2026-13251 is a high-severity path traversal vulnerability in Perfmatters, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-13251 in the wild and no public exploit code.

Affected product: Perfmatters. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-13251/ (Markdown: https://insights.sbomify.com/CVE-2026-13251/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-13251
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-13251
- OSV: https://osv.dev/vulnerability/CVE-2026-13251

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-13251/
Summaries are generated and may contain mistakes; the official description above is the record.