CVE-2025-6692: YouTube Embed WordPress Plugin XSS Flaw

CVE-2025-6692 Overview

CVE-2025-6692 is a Stored Cross-Site Scripting (XSS) vulnerability in the YouTube Embed plugin for WordPress. The flaw affects all versions up to and including 10.3. It stems from insufficient input sanitization and output escaping on the instance parameter. Authenticated attackers with Contributor-level access or higher can inject arbitrary JavaScript into pages. The injected script executes in the browser of any visitor who views the affected page. The vulnerability is tracked under CWE-79: Improper Neutralization of Input During Web Page Generation.

Critical Impact
Low-privileged WordPress contributors can plant persistent JavaScript payloads that execute against site visitors and administrators, enabling session theft, account takeover, and malicious redirects.

Affected Products

WordPress YouTube Embed plugin (youram-youtube-embed) versions ≤ 10.3
WordPress sites that permit Contributor-level or higher user registration using the plugin
Any multi-author WordPress deployment with the plugin active

Discovery Timeline

2025-07-29 - CVE-2025-6692 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-6692

Vulnerability Analysis

The YouTube Embed plugin accepts an instance parameter when rendering embed shortcodes and widget configurations. The plugin fails to sanitize this value on input and does not escape it on output. As a result, attacker-controlled markup is written directly into the rendered HTML. Any JavaScript placed inside the parameter runs in the context of the WordPress site.

Stored XSS is more impactful than reflected XSS because the payload persists in the database. Every subsequent page view triggers execution without additional attacker interaction. When an administrator views a poisoned page, the script runs with their session cookies and DOM access. Attackers can create new administrator accounts, exfiltrate nonces, or pivot to post-authentication plugin exploits.

Root Cause

The root cause is missing calls to WordPress sanitization and escaping APIs such as sanitize_text_field(), wp_kses(), and esc_attr() around the instance parameter. The plugin trusts contributor-supplied input and interpolates it into HTML output without encoding. This is a classic violation of secure output handling in WordPress plugin development.

Attack Vector

An attacker authenticates to a vulnerable WordPress site using a Contributor or higher role. The attacker crafts a post or page that includes the YouTube Embed shortcode with a malicious payload in the instance parameter. The payload is stored in the WordPress post database. When any visitor or administrator loads the page, the browser parses and executes the attacker-controlled JavaScript. See the Wordfence vulnerability analysis for further technical context.

Detection Methods for CVE-2025-6692

Indicators of Compromise

Post or page content containing <script>, onerror=, onload=, or javascript: strings inside YouTube Embed shortcode instance attributes
Unexpected WordPress user accounts created with administrator privileges after a contributor publishes content
Outbound browser requests from administrator sessions to unfamiliar domains hosting JavaScript payloads
Modifications to wp_options, wp_users, or theme files shortly after a contributor saves a post

Detection Strategies

Query the wp_posts table for shortcode occurrences containing suspicious characters: SELECT ID, post_title FROM wp_posts WHERE post_content REGEXP 'youtube.*instance=.*(<|script|onerror)';
Deploy a web application firewall rule to flag HTTP POST requests to post.php or post-new.php containing script tags inside shortcode attributes
Review audit logs for Contributor-role accounts publishing or editing content that includes the YouTube Embed shortcode

Monitoring Recommendations

Enable WordPress activity logging to capture post creation and edit events by low-privilege users
Monitor browser console errors and Content Security Policy violation reports from the WordPress admin interface
Alert on new administrator role assignments and REST API calls that modify user capabilities

How to Mitigate CVE-2025-6692

Immediate Actions Required

Upgrade the YouTube Embed plugin to a version later than 10.3 once the vendor publishes a patched release; monitor the plugin developer page for updates
Audit all posts and pages that use the YouTube Embed shortcode and remove any entries containing script tags or event handlers in the instance parameter
Review all accounts with Contributor role or higher and disable any that appear suspicious or inactive

Patch Information

At the time of publication, no fixed version is referenced in the NVD entry. Site operators should track the official WordPress plugin repository and the Wordfence advisory for a confirmed patched release. Apply the update across all WordPress environments once available.

Workarounds

Deactivate and remove the YouTube Embed plugin until a patched version is released
Restrict content submission privileges by removing Contributor and Author roles from untrusted users
Deploy a WordPress-aware web application firewall with virtual patching rules that strip script content from shortcode parameters
Enforce a strict Content Security Policy header that blocks inline script execution on front-end pages

bash

# Example: disable the plugin via WP-CLI until a patched release is available
wp plugin deactivate youram-youtube-embed
wp plugin delete youram-youtube-embed

# Audit existing posts for suspicious instance parameters
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content REGEXP 'instance=\"[^\"]*(<|script|onerror|javascript:)'"