CVE-2025-31008: YouTube Embed Plugin Stored XSS Vulnerability

CVE-2025-31008 Overview

CVE-2025-31008 is a stored Cross-Site Scripting (XSS) vulnerability in the Embeds For YouTube Plugin Support YouTube Embed (youtube-embed) WordPress plugin. The flaw affects all versions up to and including 5.3.1. It stems from improper neutralization of user-supplied input during web page generation, classified as [CWE-79]. An authenticated attacker with high privileges can inject malicious script payloads that execute in the browsers of users who view the affected pages. Successful exploitation requires user interaction and can affect resources beyond the vulnerable component due to a changed security scope.

Critical Impact
Stored script payloads execute in visitor and administrator browsers, enabling session theft, credential harvesting, and unauthorized actions within the WordPress site context.

Affected Products

WordPress plugin: Embeds For YouTube Plugin Support YouTube Embed (youtube-embed)
All versions up to and including 5.3.1
WordPress sites with the plugin installed and activated

Discovery Timeline

2025-04-09 - CVE-2025-31008 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-31008

Vulnerability Analysis

The vulnerability is a stored XSS flaw in the YouTube Embed WordPress plugin. Input supplied through plugin-managed fields is stored server-side and later rendered into web pages without adequate sanitization or output encoding. When a user loads a page containing the malicious payload, the browser executes attacker-controlled JavaScript in the site's origin.

Exploitation requires an authenticated user with elevated privileges to inject the payload, and it requires a victim to view the affected content. Because the scope changes during exploitation, injected scripts can act beyond the plugin boundary and reach other components of the WordPress application, including administrative sessions.

Root Cause

The root cause is missing or insufficient neutralization of untrusted input during web page generation, mapped to [CWE-79]. The plugin accepts input intended to configure YouTube embeds but does not consistently escape HTML, attribute, or JavaScript contexts before writing values into rendered output. As a result, HTML control characters and script constructs survive into the DOM.

Attack Vector

The attack vector is network-based. An authenticated attacker submits crafted input through the plugin's configuration or embed-management surfaces. The payload persists in the WordPress database. When an administrator or visitor loads a page that renders the stored value, the browser executes the injected script under the site's origin. Vendor-supplied technical details are limited; see the Patchstack WordPress XSS Vulnerability advisory for the affected sinks.

Detection Methods for CVE-2025-31008

Indicators of Compromise

Unexpected <script>, onerror, or onload attributes stored in WordPress postmeta or options rows associated with the youtube-embed plugin.
Outbound HTTP requests from administrator browsers to unfamiliar domains shortly after loading pages containing YouTube embeds.
New or modified WordPress administrator accounts created without a corresponding audit trail.
Browser console errors or Content Security Policy (CSP) violations referencing inline scripts on pages that host embedded YouTube content.

Detection Strategies

Query the WordPress database for plugin-managed values containing HTML tags, event handlers, or javascript: URIs.
Review web server access logs for POST requests to plugin administration endpoints followed by GET requests that render suspicious content.
Monitor authenticated administrator sessions for anomalous XHR or fetch traffic originating from pages with embedded videos.

Monitoring Recommendations

Enable and centralize WordPress audit logging for plugin configuration changes and post edits.
Deploy a Content Security Policy that restricts inline script execution and reports violations to a monitored endpoint.
Alert on privileged user activity that occurs outside of expected maintenance windows.

How to Mitigate CVE-2025-31008

Immediate Actions Required

Update the YouTube Embed plugin to a version released after 5.3.1 that addresses the vulnerability once available from the vendor.
Audit all existing plugin-managed content for stored payloads and remove any entries containing script or event-handler attributes.
Rotate WordPress administrator credentials and invalidate active sessions if compromise is suspected.
Restrict the number of accounts with privileges capable of managing the plugin.

Patch Information

Refer to the Patchstack WordPress XSS Vulnerability advisory for current patch availability and fixed version information. Apply the vendor-supplied fix through the WordPress plugin update mechanism as soon as it is published.

Workarounds

Deactivate and remove the youtube-embed plugin until a patched release is installed.
Enforce a strict Content Security Policy that blocks inline script execution on public and administrative pages.
Place the WordPress admin interface behind a web application firewall (WAF) with rules that inspect and block XSS payloads.

bash

# Example: locate installations of the affected plugin and disable it via WP-CLI
wp plugin list --name=youtube-embed --fields=name,status,version
wp plugin deactivate youtube-embed