CVE-2025-39561: LoginWP Pro Auth Bypass Vulnerability

CVE-2025-39561 Overview

CVE-2025-39561 is a Missing Authorization vulnerability (CWE-862) affecting the LoginWP Pro WordPress plugin developed by Marketing Fire, LLC. This broken access control flaw allows attackers to access functionality that is not properly constrained by Access Control Lists (ACLs), potentially enabling unauthorized actions within WordPress installations using this plugin.

Critical Impact

Unauthenticated attackers can bypass authorization controls to access restricted functionality in WordPress sites using LoginWP Pro versions through 4.0.8.5.

Affected Products

• LoginWP Pro plugin versions from n/a through 4.0.8.5
• WordPress installations with vulnerable LoginWP Pro versions
• Sites relying on LoginWP Pro for login redirect functionality

Discovery Timeline

• 2026-01-05 - CVE-2025-39561 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2025-39561

Vulnerability Analysis

This vulnerability stems from a missing authorization check within the LoginWP Pro plugin. The flaw allows attackers to access functionality that should be protected by proper access control mechanisms. Since the vulnerability is network-accessible and requires no authentication or user interaction, it presents a significant risk to WordPress sites utilizing this plugin for login management and redirection.

The impact includes potential unauthorized modification of data (integrity impact) and limited denial of service conditions (availability impact). The vulnerability does not directly expose confidential information.

Root Cause

The root cause is improper implementation of authorization controls (CWE-862). The LoginWP Pro plugin fails to verify that users have appropriate permissions before allowing access to certain functionality. This broken access control pattern allows unauthenticated users to interact with features that should require elevated privileges.

Attack Vector

The attack can be executed remotely over the network without any prior authentication or special privileges. An attacker does not need to trick users into clicking malicious links or interacting with malicious content, making this vulnerability exploitable through direct requests to the vulnerable WordPress installation.

The vulnerability allows accessing functionality not properly constrained by ACLs. This typically manifests as exposed AJAX endpoints or REST API routes that fail to verify user capabilities before executing privileged operations. Attackers can craft requests to these unprotected endpoints to perform unauthorized actions such as modifying plugin settings or accessing restricted features.

Detection Methods for CVE-2025-39561

Indicators of Compromise

• Unexpected modifications to LoginWP Pro plugin settings
• Unusual access patterns to WordPress admin AJAX endpoints from unauthenticated sources
• Log entries showing successful requests to protected functionality without valid session cookies
• Changes to login redirect rules without corresponding admin activity

Detection Strategies

• Monitor web server access logs for requests to wp-admin/admin-ajax.php with LoginWP-related action parameters from unauthenticated users
• Implement Web Application Firewall (WAF) rules to detect and block suspicious requests targeting LoginWP Pro endpoints
• Review WordPress audit logs for unauthorized configuration changes
• Deploy file integrity monitoring to detect unexpected changes to plugin files or database entries

Monitoring Recommendations

• Enable WordPress debug logging to capture detailed request information
• Configure alerts for access to sensitive LoginWP Pro functionality from non-admin IP addresses
• Establish baseline behavior for legitimate plugin usage to identify anomalies
• Regularly audit plugin settings and redirect rules for unauthorized modifications

How to Mitigate CVE-2025-39561

Immediate Actions Required

• Verify your installed LoginWP Pro version by checking WordPress admin Plugins page
• Update LoginWP Pro to a patched version (newer than 4.0.8.5) as soon as available
• Review plugin settings for any unauthorized modifications
• Temporarily disable LoginWP Pro if updates are unavailable and the plugin is not critical
• Implement WAF rules to restrict access to plugin functionality

Patch Information

This vulnerability affects LoginWP Pro versions through 4.0.8.5. Site administrators should check the Patchstack Vulnerability Report for the latest information on available patches and remediation guidance from the vendor.

Workarounds

• Temporarily deactivate the LoginWP Pro plugin if it is not essential for site operations
• Implement server-level access controls to restrict requests to plugin endpoints to authenticated administrator IPs only
• Deploy a Web Application Firewall (WAF) with rules to block unauthenticated access to LoginWP Pro functionality
• Use WordPress capability checks at the server configuration level to enforce authorization

# Apache .htaccess configuration to restrict admin-ajax access
# Add to WordPress root .htaccess file
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{REQUEST_URI} admin-ajax\.php
    RewriteCond %{QUERY_STRING} action=loginwp [NC]
    RewriteCond %{HTTP_COOKIE} !wordpress_logged_in
    RewriteRule ^ - [F,L]
</IfModule>