CVE-2026-25410: WP-CORS Authorization Bypass Vulnerability

CVE-2026-25410 Overview

A Missing Authorization vulnerability has been discovered in the WP-CORS WordPress plugin developed by tstephenson. This security flaw allows attackers to exploit incorrectly configured access control security levels, potentially enabling unauthorized modifications to CORS (Cross-Origin Resource Sharing) settings. The vulnerability stems from CWE-862 (Missing Authorization), where the plugin fails to properly verify user permissions before allowing sensitive operations.

Critical Impact

Authenticated attackers with low privileges can exploit this broken access control vulnerability to modify CORS configuration settings without proper authorization, potentially enabling cross-origin attacks against the WordPress site.

Affected Products

• WP-CORS plugin versions from n/a through <= 0.2.2
• WordPress installations using the vulnerable WP-CORS plugin

Discovery Timeline

• 2026-02-19 - CVE-2026-25410 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2026-25410

Vulnerability Analysis

This vulnerability is classified as a Missing Authorization flaw (CWE-862) that affects the WP-CORS WordPress plugin. The plugin, designed to manage Cross-Origin Resource Sharing headers for WordPress sites, fails to implement proper capability checks before allowing users to modify CORS-related settings. This broken access control condition allows authenticated users with minimal privileges to perform actions that should be restricted to administrators.

The vulnerability requires network access and an authenticated user account with low-level privileges. When exploited, an attacker can make unauthorized modifications to the site's CORS policy, though the vulnerability scope is limited to the integrity of CORS configurations without direct confidentiality or availability impacts.

Root Cause

The root cause of CVE-2026-25410 lies in the WP-CORS plugin's failure to implement proper authorization checks on sensitive administrative functions. WordPress plugins typically should verify user capabilities using functions like current_user_can() before allowing access to settings modifications. The WP-CORS plugin versions through 0.2.2 lack these essential permission verification mechanisms, allowing any authenticated user to access and modify CORS configuration options regardless of their actual role or capabilities within the WordPress installation.

Attack Vector

The attack is conducted over the network and requires the attacker to have a valid, low-privilege account on the target WordPress site. The attacker authenticates to the WordPress installation and then directly accesses the WP-CORS plugin's settings endpoints or admin pages that lack proper authorization checks.

By manipulating the CORS configuration, an attacker could potentially:

• Add malicious origins to the allowed CORS origins list
• Weaken existing CORS security restrictions
• Enable cross-origin requests from attacker-controlled domains

This could facilitate further attacks such as cross-site scripting or data exfiltration from users interacting with the compromised WordPress site.

Detection Methods for CVE-2026-25410

Indicators of Compromise

• Unexpected modifications to WP-CORS plugin settings by non-administrator users
• Unusual or unfamiliar domains appearing in the allowed CORS origins configuration
• WordPress audit logs showing settings changes by low-privilege user accounts
• Increased cross-origin requests from previously unauthorized domains

Detection Strategies

• Review WordPress user activity logs for unauthorized plugin settings modifications
• Monitor the WP-CORS configuration file or database options for unexpected changes
• Implement WordPress security plugins that track administrative action logging
• Conduct regular audits of the wp_options table for CORS-related configuration entries

Monitoring Recommendations

• Enable comprehensive audit logging on your WordPress installation to track all settings changes
• Configure alerts for any modifications to plugin settings by non-administrator accounts
• Regularly review the list of authenticated users and their assigned roles
• Monitor server access logs for unusual patterns of requests to WP-CORS administrative endpoints

How to Mitigate CVE-2026-25410

Immediate Actions Required

• Audit current WP-CORS plugin settings to ensure no unauthorized modifications have been made
• Review all WordPress user accounts and remove unnecessary low-privilege accounts
• Consider temporarily disabling the WP-CORS plugin until a patched version is available
• Implement additional access controls at the web server level to restrict plugin admin pages

Patch Information

At the time of publication, no official patch has been released for the WP-CORS plugin. The vulnerability affects all versions from n/a through <= 0.2.2. Users should monitor the Patchstack Vulnerability Report for updates and any vendor patches. Consider reaching out to the plugin developer (tstephenson) for remediation guidance.

Workarounds

• Remove the WP-CORS plugin and implement CORS headers directly through web server configuration (Apache, Nginx)
• Use .htaccess rules or Nginx configuration directives to set CORS headers without relying on the vulnerable plugin
• Restrict access to WordPress admin pages to trusted IP addresses only
• Implement a Web Application Firewall (WAF) to monitor and restrict unauthorized plugin access

# Alternative: Configure CORS headers via Apache .htaccess
# Add to your WordPress .htaccess file
<IfModule mod_headers.c>
    Header set Access-Control-Allow-Origin "https://trusted-domain.com"
    Header set Access-Control-Allow-Methods "GET, POST, OPTIONS"
    Header set Access-Control-Allow-Headers "Content-Type, Authorization"
</IfModule>