---
id: "CVE-2026-111737"
kind: "vulnerability"
aliases: ["CVE-2026-111737"]
title: "Speed Optimizer WordPress plugin: stored XSS via unescaped settings output"
severity: "low"
cvss: 3.5
epss: 0.00153
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["multisite", "package", "wordpress", "wordpress-plugin"]
not_affected_if: ["plugin-not-installed", "version-7.8.5-or-later"]
published_at: "2026-10-23T06:17:05+00:00"
first_seen_at: "2026-10-23T21:57:32+00:00"
updated_at: "2026-10-25T04:45:32+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-111737", "first_seen_at": "2026-10-23T21:57:32+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-111737", "first_seen_at": "2026-10-24T07:15:51+00:00"}]
---

# Speed Optimizer WordPress plugin: stored XSS via unescaped settings output

The Speed Optimizer WordPress plugin before 7.8.5 outputs some of its settings into the page head without sanitising or escaping them. A high-privilege user such as an admin can store script that runs in visitors' browsers, even where unfiltered_html is disabled, as in a multisite setup.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Speed Optimizer plugin version in the WordPress admin Plugins screen, or with `wp plugin get speed-optimizer --field=version` (plugin slug assumed; unknown if the sources give it)
- Review the plugin's settings that print into the page head for unescaped values

## Fix

- Update the Speed Optimizer plugin to `7.8.5` or later
- Until updated, limit who holds admin or editor roles on multisite installs

## Timeline

- 2026-10-23T21:57:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-111737
- 2026-10-24T07:15:51+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-111737

## From the sources

The Speed Optimizer  WordPress plugin before 7.8.5 does not sanitise or escape some of its settings before outputting them in the head of front-end pages, which could allow high-privilege users such as admins to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in a multisite setup).

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