CVE-2026-25402: Knowledge Base Auth Bypass Vulnerability

CVE-2026-25402 Overview

CVE-2026-25402 is a Missing Authorization vulnerability affecting the Knowledge Base for Documentation, FAQs with AI Assistance WordPress plugin (echo-knowledge-base) developed by echoplugins. This Broken Access Control vulnerability allows authenticated attackers to exploit incorrectly configured access control security levels, potentially bypassing authorization checks that should restrict certain functionality.

The vulnerability stems from missing capability checks in the plugin's authorization mechanism, enabling users with lower privilege levels to perform actions that should be restricted to administrators or other privileged roles.

Critical Impact

Authenticated attackers with low-level privileges can bypass authorization controls and potentially modify knowledge base content or settings without proper permissions.

Affected Products

• Knowledge Base for Documentation, FAQs with AI Assistance plugin versions through 16.011.0
• WordPress installations running the vulnerable echo-knowledge-base plugin
• Sites utilizing the AI Assistance features of the knowledge base plugin

Discovery Timeline

• 2026-02-19 - CVE-2026-25402 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2026-25402

Vulnerability Analysis

This vulnerability is classified under CWE-862 (Missing Authorization), indicating that the echo-knowledge-base plugin fails to properly verify whether a user has the necessary permissions before allowing certain operations to proceed. The network-based attack vector means exploitation can occur remotely through authenticated HTTP requests to the WordPress installation.

The vulnerability requires low-level authentication (PR:L), meaning an attacker must have at least subscriber-level access to the WordPress site. Once authenticated, the attacker can bypass access control mechanisms designed to protect administrative or restricted functionality within the knowledge base plugin. The impact is limited to integrity (I:L) with no direct effect on confidentiality or availability of the system.

Root Cause

The root cause of CVE-2026-25402 lies in inadequate authorization checks within the plugin's code. Specifically, the plugin fails to implement proper capability verification before executing privileged operations. WordPress plugins should utilize functions like current_user_can() to verify user permissions, but the vulnerable code paths in echo-knowledge-base versions through 16.011.0 appear to skip these essential authorization checks, allowing any authenticated user to perform actions beyond their intended privilege level.

Attack Vector

The attack is network-based and requires an authenticated session with the target WordPress installation. An attacker with subscriber or contributor-level access could craft malicious requests to the vulnerable plugin endpoints, bypassing the intended access control restrictions.

A typical exploitation scenario involves:

1. Attacker registers or compromises a low-privilege WordPress account
2. Attacker identifies vulnerable AJAX actions or REST API endpoints exposed by the echo-knowledge-base plugin
3. Attacker submits crafted requests to these endpoints without proper authorization checks
4. The plugin processes the request, allowing unauthorized modifications to knowledge base content or configuration settings

For detailed technical information about this vulnerability, refer to the Patchstack Vulnerability Advisory.

Detection Methods for CVE-2026-25402

Indicators of Compromise

• Unexpected modifications to knowledge base articles or FAQ content by non-administrative users
• Audit logs showing configuration changes initiated by low-privilege accounts
• Unusual POST requests to echo-knowledge-base AJAX handlers from subscriber accounts
• Knowledge base settings modified without corresponding administrator activity

Detection Strategies

• Monitor WordPress audit logs for actions performed by the echo-knowledge-base plugin initiated by non-admin users
• Implement web application firewall (WAF) rules to detect abnormal request patterns targeting plugin endpoints
• Review user activity logs for privilege escalation patterns or unauthorized content modifications
• Enable WordPress security plugins that track user capability usage and flag unauthorized operations

Monitoring Recommendations

• Configure real-time alerting for knowledge base modifications by non-administrator users
• Establish baseline activity patterns for the echo-knowledge-base plugin and alert on deviations
• Monitor HTTP POST requests to /wp-admin/admin-ajax.php containing echo-knowledge-base action parameters

How to Mitigate CVE-2026-25402

Immediate Actions Required

• Update the Knowledge Base for Documentation, FAQs with AI Assistance plugin to a version newer than 16.011.0 that addresses this vulnerability
• Audit existing user accounts and remove unnecessary subscriber or contributor access
• Review recent knowledge base changes for unauthorized modifications
• Implement additional access controls at the WordPress or server level as a temporary measure

Patch Information

Organizations using the echo-knowledge-base WordPress plugin should update to the latest available version that addresses this Missing Authorization vulnerability. Check the Patchstack Vulnerability Advisory for the latest patching guidance from the vendor.

Workarounds

• Restrict user registration on the WordPress site to prevent attackers from obtaining authenticated access
• Temporarily disable the echo-knowledge-base plugin until a patch can be applied
• Implement server-level access controls to restrict POST requests to vulnerable endpoints
• Use a WordPress security plugin to enforce strict capability checks on plugin actions

# Configuration example - Restrict access to plugin endpoints via .htaccess
# Add to WordPress .htaccess file as temporary mitigation
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{REQUEST_METHOD} POST
    RewriteCond %{QUERY_STRING} action=.*echo.* [NC]
    RewriteCond %{REMOTE_ADDR} !^192\.168\.1\.100$
    RewriteRule ^wp-admin/admin-ajax\.php$ - [F,L]
</IfModule>