john-dagelmore WPSpeed Plugin up to 2.6.10 on WordPress LightImages HTML optimizer optimize nickname/display_name HTML injection

Summaryinfo

A vulnerability marked as problematic has been reported in john-dagelmore WPSpeed Plugin up to 2.6.10. This issue affects the function Dispatcher::runOptimize/LightImages::optimize of the component LightImages HTML optimizer. Performing a manipulation of the argument nickname/display_name results in HTML injection. This vulnerability was named CVE-2026-118784. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic has been found in john-dagelmore WPSpeed Plugin up to 2.6.10. This affects the function Dispatcher::runOptimize/LightImages::optimize of the component LightImages HTML optimizer. The manipulation of the argument nickname/display_name with an unknown input leads to a html injection vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. The summary by CVE is:

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.

The advisory is shared at wordfence.com. This vulnerability is uniquely identified as CVE-2026-118784 since 10/28/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-119035). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• john-dagelmore

Name

• WPSpeed Plugin

Version

• 2.6.0
• 2.6.1
• 2.6.2
• 2.6.3
• 2.6.4
• 2.6.5
• 2.6.6
• 2.6.7
• 2.6.8
• 2.6.9
• 2.6.10

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

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• 🔒
• 🔒

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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