CVE-2025-46501 Overview
CVE-2025-46501 is a stored cross-site scripting (XSS) vulnerability in the Mixcloud Embed WordPress plugin developed by biancardi. The flaw affects all plugin versions up to and including 2.2.0. Attackers with contributor-level access or higher can inject malicious JavaScript that persists in the database and executes in the browsers of site visitors and administrators. The vulnerability is classified under CWE-79 for improper neutralization of input during web page generation.
Critical Impact
Authenticated attackers can inject persistent JavaScript payloads that execute in victim browsers, enabling session theft, administrative account takeover, and arbitrary actions performed in the context of authenticated WordPress users.
Affected Products
- biancardi Mixcloud Embed plugin for WordPress
- All versions from initial release through 2.2.0
- WordPress sites with the plugin activated and shortcode functionality exposed
Discovery Timeline
- 2025-04-24 - CVE-2025-46501 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-46501
Vulnerability Analysis
The Mixcloud Embed plugin fails to properly neutralize user-supplied input before rendering it within generated web pages. This allows an authenticated attacker to inject HTML and JavaScript that the plugin stores and later renders without sanitization or output encoding. When any user loads a page containing the injected payload, the browser executes the attacker-controlled script within the site's origin.
Exploitation requires low privileges and user interaction, but the scope change indicates the payload can affect resources beyond the vulnerable plugin's security context. Successful exploitation can compromise the confidentiality, integrity, and availability of the WordPress site and its visitors.
Root Cause
The root cause is missing or insufficient input validation and output escaping within the plugin's shortcode or embed rendering logic. The plugin accepts attributes or content from authenticated users and writes them into the DOM without applying WordPress sanitization APIs such as esc_attr(), esc_html(), or wp_kses(). Because the payload persists in the WordPress database, every subsequent page render replays the attack against new visitors.
Attack Vector
An authenticated user with post-editing privileges submits a Mixcloud embed shortcode or field containing crafted HTML with an event handler such as onerror or a <script> tag. The plugin stores the value unmodified. When an administrator or visitor loads the affected post, the browser parses the payload and executes attacker-controlled JavaScript. The attacker can hijack sessions, exfiltrate cookies, pivot to administrative actions through the WordPress REST API, or plant persistent backdoors in the site theme.
See the Patchstack Vulnerability Report for additional technical detail.
Detection Methods for CVE-2025-46501
Indicators of Compromise
- WordPress post or postmeta rows containing <script>, onerror=, onload=, or javascript: strings within Mixcloud embed shortcodes
- Unexpected outbound requests from visitor browsers to attacker-controlled domains after loading pages with Mixcloud embeds
- New administrator accounts or modified user roles created shortly after a contributor edits content containing embeds
- Modifications to theme files, plugin files, or wp_options entries following visits by authenticated administrators
Detection Strategies
- Audit the wp_posts and wp_postmeta tables for shortcode attributes containing HTML tags or JavaScript event handlers
- Deploy a Content Security Policy in report-only mode to surface inline script violations originating from post content
- Review web server access logs for POST requests to /wp-admin/post.php and /wp-json/wp/v2/posts containing suspicious payload patterns
Monitoring Recommendations
- Monitor WordPress user role changes and administrator account creation events in real time
- Alert on file integrity changes to wp-config.php, active theme files, and the mu-plugins directory
- Track browser telemetry for anomalous script execution and cross-origin requests from authenticated admin sessions
How to Mitigate CVE-2025-46501
Immediate Actions Required
- Deactivate the Mixcloud Embed plugin until a patched release is confirmed available and installed
- Restrict contributor and author account provisioning and enforce multi-factor authentication for all editorial roles
- Audit existing posts for previously injected payloads and remove any suspicious embed content
- Rotate WordPress administrator passwords and invalidate active sessions after remediation
Patch Information
No fixed version is identified in the referenced advisory at the time of publication. Consult the Patchstack Vulnerability Report and the plugin's WordPress.org page for updated release information. Apply the vendor patch as soon as it becomes available.
Workarounds
- Remove the plugin entirely and replace embeds with the native WordPress oEmbed handler for Mixcloud URLs
- Deploy a Web Application Firewall rule that blocks HTML and JavaScript payloads within Mixcloud shortcode attributes
- Enforce a strict Content Security Policy that disallows inline scripts and untrusted script sources
- Limit editorial capabilities so untrusted users cannot publish posts containing shortcodes
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.