Perfmatters <= 2.5.9 — Authenticated (Subscriber+) Arbitrary File Overwrite via 'snippets' Parameter

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Perfmatters.
• No admin access? Run a passive check of your site. It reads public files only.

What to do

1. Update to version 2.6.0, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch Perfmatters to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to h0xilo.

The Perfmatters plugin for WordPress is vulnerable to arbitrary file overwrite via path traversal in all versions up to, and including, 2.5.9. This is due to the `PMCS::action_handler()` method processing the bulk action `activate`/`deactivate` handlers without any authorization check or nonce verification. The `$_GET['snippets'][]` values are passed unsanitized to `Snippet::activate()`/`Snippet::deactivate()` which call `Snippet::update()` then `file_put_contents()` with the traversed path. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite arbitrary files on the server with a fixed PHP docblock content, potentially causing denial of service by corrupting critical files like `.htaccess` or `index.php`.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

• Advisorywordfence.com

Related CVEs

Timeline

1. Apr 9, 2026

   CVE published

   Severity high, CVSS 8.1

2. Nov 13, 2026

   Record last updated