Vulnerability · Published Nov 7, 2026 · Assigned by Wordfence
CVE-2026-118784WPSpeed <= 2.6.10 - Authenticated (Subscriber+) Stored Cross-Site Scripting via User Nickname/Display Name
Medium 6.4
In plain English
A medium-severity cross-site scripting in WPSpeed – WordPress Speed, Cache & Performance Optimization (Core Web Vitals, PageSpeed 100) from john-dagelmore. There are no confirmed reports of exploitation so far.
Official description
The WPSpeed plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.6.10 This is due to a combination of two issues in the LightImages HTML optimizer: (1) Dispatcher::runOptimize() decides whether the current request is the site's home page by comparing only the URL path from REQUEST_URI against the path of the home URL, so on a plain-permalinks install the author archive URL /?author=<ID> is treated as the home page and the LightImages optimizer runs on it; and (2) LightImages::optimize() calls html_entity_decode() across the entire serialized DOMDocument output under the default-enabled img_processing_entity_decode setting, converting any entity-encoded markup present as plain text in the page (including WordPress's rendered author title) into live HTML. This makes it possible for authenticated attackers, with Subscriber-level access and above, to store entity-encoded markup in their own nickname/display_name through the normal profile endpoint and have that markup rehydrated into executing script when any logged-out visitor loads their author archive.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| john-dagelmore | WPSpeed – WordPress Speed, Cache & Performance Optimization (Core Web Vitals, PageSpeed 100) | 0 – through 2.6.10 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/47aa1a74-4189-4521-ba6e-e91a06b8f5a6?source=cve
- https://plugins.trac.wordpress.org/browser/wpspeed/tags/2.6.10/src/Dispatcher.php#L170
- https://plugins.trac.wordpress.org/browser/wpspeed/tags/2.6.10/src/Core/LightImages.php#L628
- https://plugins.trac.wordpress.org/browser/wpspeed/tags/2.6.10/src/Core/Optimize.php#L152
- https://plugins.trac.wordpress.org/changeset/3771695/wpspeed/trunk/src/Core/LightImages.php