CVE-2025-26877
📋 TL;DR
This stored cross-site scripting (XSS) vulnerability in the Rustaurius Front End Users WordPress plugin allows attackers to inject malicious scripts into web pages. When users view affected pages, the scripts execute in their browsers, potentially stealing credentials or performing unauthorized actions. All WordPress sites using Front End Users plugin versions up to 3.2.30 are affected.
💻 Affected Systems
- Rustaurius Front End Users WordPress Plugin
📦 What is this software?
Front End Users by Etoilewebdesign
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, take over WordPress sites, deface websites, or redirect visitors to malicious sites.
Likely Case
Attackers steal user session cookies or credentials, perform actions on behalf of authenticated users, or deploy malware to visitors.
If Mitigated
With proper input validation and output encoding, malicious scripts would be neutralized before reaching users.
🎯 Exploit Status
Stored XSS vulnerabilities are commonly exploited, though specific exploit details aren't publicly documented for this CVE.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.2.31 or later
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'Front End Users' plugin. 4. Click 'Update Now' if update available. 5. Alternatively, download latest version from WordPress repository and replace plugin files.
🔧 Temporary Workarounds
Input Sanitization Filter
allAdd custom input sanitization for plugin fields using WordPress hooks
Add to theme's functions.php or custom plugin: add_filter('preprocess_comment', 'sanitize_frontend_users_input'); function sanitize_frontend_users_input($data) { foreach($data as $key => $value) { $data[$key] = sanitize_text_field($value); } return $data; }
🧯 If You Can't Patch
- Disable the Front End Users plugin completely until patched
- Implement web application firewall (WAF) rules to block XSS payloads targeting the plugin
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin → Plugins → Installed Plugins, find 'Front End Users' and check version numberCheck Version:
wp plugin list --name='front-end-only-users' --field=version (if WP-CLI installed)Verify Fix Applied:
Verify plugin version is 3.2.31 or higher in WordPress admin panel📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to plugin endpoints with script tags in parameters
- Multiple failed login attempts following suspicious plugin activity
Network Indicators:
- HTTP requests containing <script> tags or javascript: URIs targeting plugin endpoints
- Unexpected outbound connections from WordPress site after plugin interaction
SIEM Query:
source="wordpress.log" AND ("front-end-users" OR "frontendusers") AND ("<script>" OR "javascript:" OR "onerror=" OR "onload=")