CVE-2025-24687: Show/Hide Shortcode Plugin XSS Vulnerability

CVE-2025-24687 Overview

CVE-2025-24687 is a stored Cross-Site Scripting (XSS) vulnerability in the Lars Wallenborn Show/Hide Shortcode plugin for WordPress. The flaw affects all versions of the showhide-shortcode plugin up to and including 1.0.0. The plugin fails to properly neutralize user-supplied input during web page generation, allowing attackers with low privileges to inject persistent JavaScript payloads. The stored payload executes in the browser of any user viewing the affected page. This vulnerability is classified under CWE-79.

Critical Impact
Authenticated attackers can inject stored JavaScript that executes in visitors' browsers, enabling session theft, unauthorized actions, and potential site takeover through admin session hijacking.

Affected Products

Lars Wallenborn Show/Hide Shortcode plugin for WordPress
All versions from initial release through 1.0.0
WordPress sites with the showhide-shortcode plugin installed and activated

Discovery Timeline

2025-01-24 - CVE-2025-24687 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-24687

Vulnerability Analysis

The Show/Hide Shortcode plugin provides WordPress content authors with shortcodes that toggle content visibility. The plugin accepts user-supplied parameters and content but does not apply adequate output encoding or input sanitization. This gap enables Stored Cross-Site Scripting under [CWE-79].

An attacker with contributor-level or higher privileges submits content containing a malicious payload through the plugin's shortcode. The payload is persisted in the WordPress database as part of post or page content. When any visitor renders the affected page, the browser interprets the injected markup and executes attacker-controlled JavaScript in the site's origin.

The scope changes from the vulnerable component to the victim's browser session, which is why the impact reaches confidentiality, integrity, and availability. User interaction is required, meaning a victim must load the page containing the stored payload.

Root Cause

The root cause is improper neutralization of input during web page generation. The plugin renders shortcode attributes and enclosed content into the DOM without escaping HTML control characters such as <, >, and ". Standard WordPress escaping functions like esc_html(), esc_attr(), and wp_kses() were not applied to attacker-influenced fields before output.

Attack Vector

Exploitation occurs over the network against WordPress instances running the vulnerable plugin. The attacker authenticates as a low-privileged user permitted to publish or edit posts. The attacker embeds the showhide shortcode with a crafted attribute or body containing script content. Once published, the payload triggers whenever a moderator, administrator, or site visitor loads the page. Successful exploitation can lead to session cookie theft, forced administrative actions via CSRF, or delivery of secondary payloads to visitors.

No verified proof-of-concept code is publicly available. Technical details are documented in the Patchstack Plugin Vulnerability Report.

Detection Methods for CVE-2025-24687

Indicators of Compromise

Post or page content containing <script> tags, on* event handlers, or javascript: URIs within [showhide] shortcode attributes or body
Unexpected outbound requests from browser sessions loading WordPress pages that use the plugin
New administrator accounts or role changes shortly after a low-privileged user published shortcode content
WordPress audit log entries showing content edits by contributor or author accounts targeting pages that render for administrators

Detection Strategies

Query the wp_posts table for post_content values containing [showhide combined with script indicators such as <script, onerror=, or onload=
Enable Content Security Policy (CSP) reporting to surface script executions from inline sources on pages using the plugin
Review web server access logs for POST requests to wp-admin/post.php or the REST API that include suspicious shortcode payloads

Monitoring Recommendations

Alert on privilege escalations and admin user creation events following content edits by low-privileged authors
Monitor WordPress plugin inventory for the presence of showhide-shortcode and track its installed version
Track browser telemetry for anomalous JavaScript execution on public-facing WordPress pages

How to Mitigate CVE-2025-24687

Immediate Actions Required

Deactivate and remove the Show/Hide Shortcode plugin from all WordPress instances until a patched release is confirmed
Audit all posts and pages containing the [showhide] shortcode for injected script content and remove malicious payloads
Review contributor, author, and editor accounts for unauthorized activity or unfamiliar users
Force password resets and invalidate active sessions for administrator accounts that may have viewed compromised pages

Patch Information

At the time of publication, no fixed version has been identified. The vulnerability affects the showhide-shortcode plugin from initial release through version 1.0.0. Site owners should monitor the Patchstack advisory and the plugin's WordPress.org listing for updates.

Workarounds

Uninstall the plugin and replace it with a maintained alternative that applies proper output escaping
Restrict content publishing capabilities to trusted users only by revoking contributor and author roles for untrusted accounts
Deploy a Web Application Firewall (WAF) rule to block script tags and JavaScript event handlers inside shortcode attributes
Implement a strict Content Security Policy that disallows inline scripts on public pages

bash

# Configuration example: locate and disable the vulnerable plugin via WP-CLI
wp plugin list --name=showhide-shortcode --format=table
wp plugin deactivate showhide-shortcode
wp plugin uninstall showhide-shortcode

# Search for potentially malicious stored payloads
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%[showhide%' AND (post_content LIKE '%<script%' OR post_content LIKE '%onerror=%' OR post_content LIKE '%onload=%');"