CVE-2025-49051: Hide Text Shortcode Plugin XSS Vulnerability

CVE-2025-49051 Overview

CVE-2025-49051 is a stored cross-site scripting (XSS) vulnerability in the Hide Text Shortcode WordPress plugin developed by biscia7. The flaw affects all versions up to and including 1.1. It stems from improper neutralization of user-supplied input during web page generation, classified under [CWE-79]. An authenticated attacker with low privileges can inject persistent JavaScript payloads that execute in the browser of any user who views the affected page. Because the injected script executes in a scope change, it can impact users beyond the vulnerable component.

Critical Impact
An authenticated contributor-level attacker can inject persistent JavaScript that executes against site visitors and administrators, enabling session theft, forced actions, or redirection to attacker-controlled resources.

Affected Products

biscia7 Hide Text Shortcode plugin for WordPress
All versions from initial release through 1.1
WordPress sites with the hide-text-shortcode plugin activated

Discovery Timeline

2025-08-14 - CVE-2025-49051 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-49051

Vulnerability Analysis

The Hide Text Shortcode plugin fails to sanitize input passed through shortcode attributes or content before rendering it in generated HTML output. When a contributor or higher-privileged user submits content containing crafted markup through the shortcode, the payload is stored in the WordPress database. The payload later executes when any visitor loads the page containing the shortcode. This qualifies as stored XSS because the malicious script persists across sessions and affects all viewers.

Exploitation requires user interaction, since a target must load a page containing the injected shortcode. The scope change indicates that the injected script can affect resources outside the vulnerable plugin's security context, including the broader WordPress admin session.

Root Cause

The root cause is missing output encoding and input sanitization in the shortcode handler. WordPress provides functions such as esc_html(), esc_attr(), and wp_kses() for neutralizing HTML control characters, but the plugin does not apply them consistently to shortcode-supplied values before echoing them into the rendered page.

Attack Vector

An authenticated attacker with contributor-level access or higher submits a post or page that uses the hide-text-shortcode shortcode with a JavaScript payload embedded in an attribute or the shortcode body. Once the content is saved and published or previewed by an administrator, the malicious script executes in the victim's browser under the site's origin. Attackers can leverage this to steal authentication cookies, perform administrative actions via forged requests, or pivot to further compromise. No verified public exploit code is available at this time. For technical details, see the Patchstack Vulnerability Report.

Detection Methods for CVE-2025-49051

Indicators of Compromise

Post or page content in the wp_posts table containing <script>, onerror=, or javascript: payloads within [hide-text-shortcode] shortcode boundaries
Unexpected outbound requests from administrator browsers to unfamiliar domains after viewing plugin-rendered content
New or modified administrator accounts created shortly after a low-privileged user submitted content

Detection Strategies

Audit all posts, pages, and custom post types for shortcode invocations containing HTML tags or encoded script constructs in attributes
Inspect web server access logs for POST requests to /wp-admin/post.php from contributor-level accounts followed by administrator page views
Deploy a web application firewall rule that flags shortcode attributes containing angle brackets, event handlers, or javascript: schemes

Monitoring Recommendations

Enable WordPress activity logging to track content creation and modification by non-administrator accounts
Monitor browser-generated telemetry from administrator sessions for anomalous script execution or DOM modifications
Alert on plugin file integrity changes and unexpected database writes to wp_posts and wp_options

How to Mitigate CVE-2025-49051

Immediate Actions Required

Deactivate and remove the Hide Text Shortcode plugin until a patched version is released by the vendor
Review all existing content that uses the shortcode and remove or sanitize any suspicious payloads before republishing
Rotate WordPress administrator credentials and invalidate active sessions if unauthorized content submissions are detected

Patch Information

At the time of publication, no fixed version has been identified in the NVD entry. The advisory indicates the vulnerability affects all versions through 1.1. Site owners should monitor the Patchstack Vulnerability Report and the plugin's WordPress.org page for a patched release.

Workarounds

Restrict content authoring to trusted administrator accounts and revoke contributor or author roles from untrusted users
Deploy a WAF with rules that block script tags and event handler attributes in POST parameters targeting /wp-admin/
Enforce a strict Content Security Policy that disallows inline scripts to reduce the impact of successful injection

bash

# Configuration example: disable the vulnerable plugin via WP-CLI
wp plugin deactivate hide-text-shortcode
wp plugin delete hide-text-shortcode

# Example nginx rule to block script tags in admin POSTs
if ($request_method = POST) {
    if ($request_body ~* "<script|onerror=|javascript:") {
        return 403;
    }
}