WP Compress <= 7.25.00 — Unauthenticated Privilege Escalation to 'group'/'setting'/'value' Parameters on comms Endpoint

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under WP Compress – Instant Performance & Speed Optimization.
• No admin access? Run a passive check of your site. It reads public files only.
• No account is needed to exploit this. Treat any exposed site on an affected version as at risk.

What to do

1. Update to version 7.26.00, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch WP Compress – Instant Performance & Speed Optimization to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Wordfence PRISM.

The WP Compress – Instant Performance & Speed Optimization plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 7.25.00 The vulnerability exists because the `start_comms` dispatcher (`wps_ic_comms::start_comms`), hooked on every front-end request, gates access only by comparing the caller-supplied `apikey` parameter against the stored plugin API key with no WordPress capability check and no nonce verification, then passes the unvalidated `group`, `setting`, and `value` parameters directly to `change_setting()`, which writes them into the `WPS_IC_SETTINGS` option without an allow-list. This makes it possible for unauthenticated attackers to write arbitrary permission keys into the plugin's settings, causing `wps_ic_users::checkAndAddCaps()` to grant any WordPress role — including Subscriber — the `manage_wpc_settings` capability and thereby achieve plugin-administrator-equivalent control over the plugin's optimization, CDN, and critical-CSS surfaces. The API key required to pass the authorization check can itself be obtained without authentication via the `wpc_send_critical_remote` nopriv AJAX action: when the external critical-CSS service returns an `apiResults` field, `initCritical()` echoes the stored plugin API key back to the caller in a `wp_send_json_success` response, completing the exploit chain entirely without a WordPress login.

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. Oct 15, 2026

   CVE published

   Severity medium, CVSS 4.8

2. Nov 13, 2026

   Record last updated