CVE-2025-39528: Rescue Shortcodes Stored XSS Vulnerability

CVE-2025-39528 Overview

CVE-2025-39528 is a stored Cross-Site Scripting (XSS) vulnerability in the Rescue Themes Rescue Shortcodes plugin for WordPress. The flaw stems from improper neutralization of user input during web page generation [CWE-79]. All versions through 3.1 are affected. An authenticated attacker with low privileges can inject malicious JavaScript that persists on the server and executes in the browser of any user who views the affected page. The scope change in the CVSS vector indicates that the injected script can affect resources beyond the vulnerable component, including administrative sessions.

Critical Impact
Authenticated attackers can inject persistent JavaScript into WordPress pages, enabling session hijacking, credential theft, and administrative account compromise through social-engineered clicks.

Affected Products

Rescue Themes Rescue Shortcodes plugin for WordPress
All versions from n/a through 3.1
WordPress sites with the plugin installed and active

Discovery Timeline

2025-04-16 - CVE-2025-39528 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-39528

Vulnerability Analysis

The Rescue Shortcodes plugin fails to sanitize or escape user-supplied input before rendering it in generated web pages. When an authenticated contributor-level or higher user submits content through a vulnerable shortcode parameter, the input is stored in the WordPress database. The payload is later rendered without encoding, causing the browser to parse attacker-controlled markup as executable script.

Stored XSS in WordPress plugins typically enables attackers to steal authentication cookies, perform actions on behalf of administrators through forged requests, or redirect visitors to attacker-controlled infrastructure. The scope-changed component of the vulnerability indicates the injected payload affects resources outside the vulnerable plugin, including the WordPress admin dashboard and other authenticated sessions.

Root Cause

The root cause is missing or insufficient output encoding on shortcode attributes or content fields handled by the plugin. WordPress provides sanitization helpers such as esc_html(), esc_attr(), and wp_kses(), but the plugin does not apply these consistently before echoing user input into page output.

Attack Vector

Exploitation requires an authenticated account with permission to use the vulnerable shortcode and a victim who views the resulting page. The attacker crafts a shortcode payload containing JavaScript, publishes it to a post or page, and waits for an administrator or other user to render the content. Full exploitation details are available in the Patchstack Vulnerability Report.

Detection Methods for CVE-2025-39528

Indicators of Compromise

Unexpected <script> tags, onerror, onload, or javascript: URIs stored in wp_posts content or postmeta associated with Rescue Shortcodes output
Outbound requests from administrator browsers to unfamiliar domains shortly after loading pages containing the plugin's shortcodes
New administrator accounts or modified user roles created without a corresponding audit trail

Detection Strategies

Query the WordPress database for shortcode entries containing suspicious HTML event handlers or script tags
Review web server access logs for POST requests to post.php or admin-ajax.php carrying encoded script payloads from low-privilege accounts
Compare installed plugin versions against the fixed release and flag any site running Rescue Shortcodes at version 3.1 or earlier

Monitoring Recommendations

Enable WordPress audit logging to track shortcode edits and post revisions by non-administrator users
Deploy a Web Application Firewall with rules that identify common XSS payload patterns in shortcode parameters
Monitor administrator session anomalies, including unexpected cookie reuse or session creation from new IP addresses

How to Mitigate CVE-2025-39528

Immediate Actions Required

Update the Rescue Shortcodes plugin to a version later than 3.1 once the vendor releases a patched build
Audit existing posts and pages for malicious shortcode payloads and remove any injected scripts
Restrict shortcode-authoring privileges to trusted users until a fix is confirmed

Patch Information

At the time of publication, no fixed version is listed in the NVD entry. Monitor the Patchstack Vulnerability Report and the plugin's WordPress.org listing for an official patched release.

Workarounds

Deactivate and remove the Rescue Shortcodes plugin if no business-critical content depends on it
Configure a Web Application Firewall rule to strip or block script payloads submitted to shortcode fields
Enforce the principle of least privilege for WordPress editorial roles to reduce the pool of users who can introduce stored payloads

bash

# Disable the vulnerable plugin via WP-CLI
wp plugin deactivate rescue-shortcodes
wp plugin delete rescue-shortcodes

# Audit stored posts for script injection patterns
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content REGEXP '<script|onerror=|onload=|javascript:';"