CVE-2026-25035: Contest Gallery Auth Bypass Vulnerability

CVE-2026-25035 Overview

CVE-2026-25035 is a critical Authentication Bypass Using an Alternate Path or Channel vulnerability in the Contest Gallery WordPress plugin developed by Wasiliy Strecker / ContestGallery. This vulnerability allows attackers to abuse authentication mechanisms, potentially leading to complete account takeover on affected WordPress installations.

Critical Impact

This authentication bypass vulnerability enables unauthenticated attackers to gain unauthorized access to user accounts, including administrator accounts, potentially leading to complete WordPress site compromise.

Affected Products

• Contest Gallery WordPress plugin versions through 28.1.2.2
• WordPress installations using vulnerable Contest Gallery plugin versions

Discovery Timeline

• 2026-03-25 - CVE-2026-25035 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2026-25035

Vulnerability Analysis

This vulnerability is classified under CWE-288 (Authentication Bypass Using an Alternate Path or Channel). The flaw exists in the Contest Gallery plugin's authentication handling mechanism, where an alternate authentication path allows attackers to bypass normal authentication controls entirely.

The vulnerability enables authentication abuse attacks where an attacker can circumvent the standard login process and gain access to user accounts without proper credentials. Given the network-based attack vector with no privileges required and no user interaction needed, this vulnerability presents a significant risk to any WordPress site running the affected plugin versions.

The impact encompasses complete compromise of confidentiality, integrity, and availability of affected systems, making this a high-priority vulnerability for remediation.

Root Cause

The root cause of CVE-2026-25035 lies in the Contest Gallery plugin's failure to properly validate authentication through all available pathways. The plugin exposes an alternate authentication channel that does not enforce the same security controls as the primary authentication mechanism, allowing attackers to bypass credential verification entirely.

This design flaw represents a fundamental security weakness where the authentication logic can be circumvented through an unprotected alternate path, enabling account takeover without requiring valid user credentials.

Attack Vector

The attack vector for this vulnerability is network-based, meaning attackers can exploit it remotely without any prior authentication or user interaction. An attacker can target any publicly accessible WordPress site running a vulnerable version of the Contest Gallery plugin.

The exploitation involves accessing the alternate authentication channel exposed by the plugin, which lacks proper security controls. Since no privileges are required and the attack complexity is low, this vulnerability is particularly dangerous in environments where the plugin is deployed.

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

Detection Methods for CVE-2026-25035

Indicators of Compromise

• Unexpected administrative account access or session creation without corresponding login events
• Suspicious authentication-related requests to Contest Gallery plugin endpoints
• Unauthorized modifications to WordPress user accounts or elevated privileges
• Access logs showing requests to alternate authentication paths within the plugin

Detection Strategies

• Monitor WordPress authentication logs for anomalous login patterns or authentication bypasses
• Implement Web Application Firewall (WAF) rules to detect and block suspicious authentication requests
• Review access logs for requests targeting Contest Gallery plugin authentication endpoints
• Deploy intrusion detection systems configured to alert on authentication bypass patterns

Monitoring Recommendations

• Enable detailed logging for all WordPress authentication events and plugin activity
• Set up alerts for new administrator account creation or privilege escalation events
• Monitor for unusual patterns in user session creation without corresponding credential submission
• Regularly audit WordPress user accounts and access permissions for unauthorized changes

How to Mitigate CVE-2026-25035

Immediate Actions Required

• Update the Contest Gallery plugin to the latest patched version immediately
• Review WordPress user accounts for any unauthorized access or suspicious activity
• Temporarily disable the Contest Gallery plugin if an update is not immediately available
• Conduct a security audit of affected WordPress installations for signs of compromise

Patch Information

Organizations should update the Contest Gallery plugin to a version newer than 28.1.2.2 that addresses this authentication bypass vulnerability. Check the Patchstack Vulnerability Advisory for the latest patch information and remediation guidance.

Verify the update has been successfully applied by confirming the plugin version in the WordPress admin dashboard.

Workarounds

• Disable the Contest Gallery plugin entirely until a patch can be applied
• Implement WAF rules to block suspicious requests to Contest Gallery authentication endpoints
• Restrict access to the WordPress admin area via IP allowlisting where feasible
• Enable multi-factor authentication for all WordPress administrator accounts as a defense-in-depth measure

# Disable Contest Gallery plugin via WP-CLI
wp plugin deactivate contest-gallery

# Verify plugin status
wp plugin list --name=contest-gallery --fields=name,status,version