# Speed Optimizer <= 7.8.4 - Authenticated (Administrator+) Stored Cross-Site Scripting via DNS Prefetch and Font Preload URLs

- **ID:** WPSEC-2026-1373
- **Plugin:** Speed Optimizer – The All-In-One Performance-Boosting Plugin (`sg-cachepress`), https://wordpress.org/plugins/sg-cachepress/
- **Affected versions:** from 5.6.0 before 7.8.5
- **Fixed in:** 7.8.5 (Update to 7.8.5 or later.)
- **Severity:** Medium 4.4 (CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Medium, affected versions Medium (as of 2026-10-21)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/sg-cachepress
- **Fix released:** 2026-10-20
- **Published:** 2026-10-21
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1373/

## Description

The Speed Optimizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the DNS prefetch URLs and font preload URLs settings (including values loaded through the settings import) in all versions up to, and including, 7.8.4, due to insufficient input sanitization and output escaping when the stored URLs are printed into <link> tags in the page head. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts that execute on every front-end page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

## References

- https://wpsec.com/vuln/WPSEC-2026-1373/
- https://plugins.svn.wordpress.org/sg-cachepress/tags/7.8.5/
- https://wordpress.org/plugins/sg-cachepress/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1373/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.