CVE-2026-16055 in Contest Gallery Plugin
Summary
by MITRE • 08/05/2026
The Contest Gallery WordPress plugin before 30.0.7 does not route its front-end login through the standard WordPress authentication flow, issuing an authentication cookie directly after the password check, which bypasses installed brute-force-protection and two-factor-authentication Contest Gallery WordPress plugin before 30.0.7 and enables unlimited, unthrottled password guessing against any account (including administrators) up to full account takeover.
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Analysis
by VulDB Data Team • 08/05/2026
The Contest Gallery WordPress plugin vulnerability represents a critical security flaw that fundamentally undermines the authentication mechanisms of WordPress installations. This issue affects versions prior to 30.0.7 and stems from the plugin's non-standard approach to user authentication, where it bypasses the established WordPress authentication pipeline entirely. The vulnerability creates an exploitable condition that allows attackers to circumvent all built-in security measures designed to protect against unauthorized access attempts.
The technical implementation of this flaw involves the plugin's direct issuance of authentication cookies following password verification without proper integration with WordPress's standard authentication flow. This approach completely eliminates the protection mechanisms that WordPress provides, including brute-force protection systems and two-factor authentication implementations. The vulnerability manifests as a failure to properly validate authentication requests through the WordPress core authentication framework, creating an authentication bypass that operates outside the normal security boundaries of the platform.
From an operational perspective, this vulnerability enables unlimited password guessing attacks against any user account within the WordPress installation, including high-privilege administrator accounts. Attackers can perform continuous brute-force attempts without encountering rate limiting or account lockout mechanisms that would normally protect against such attacks. The lack of throttling and protection measures means that automated attack tools can systematically work through password dictionaries or generate random credentials at unlimited speed until they successfully compromise an account.
The security implications extend beyond simple credential theft to full system compromise, as administrators typically possess elevated privileges that allow them to modify core system components, install malicious plugins, access sensitive data, and potentially use compromised accounts for further attacks within the network. This vulnerability directly violates the principle of least privilege and authentication integrity that forms the foundation of secure web application design.
Organizations affected by this vulnerability should immediately update to Contest Gallery plugin version 30.0.7 or later, which implements proper WordPress authentication integration. System administrators should also review existing user accounts for potential compromise, implement additional monitoring for unusual login patterns, and ensure that all WordPress installations maintain current security patches. The vulnerability aligns with CWE-613 weakness categories related to insufficient session validation and improper authentication handling.
Security teams should consider implementing additional protective measures such as IP-based restrictions, enhanced logging of authentication attempts, and network-level controls to limit access to authentication endpoints. The ATT&CK framework categorizes this vulnerability under credential access techniques, specifically targeting the T1110.003 sub-technique for Brute Force attacks. Organizations should also conduct comprehensive security assessments to identify other plugins or components that may be implementing similar non-standard authentication flows.
This vulnerability demonstrates the importance of maintaining proper integration with established security frameworks and the dangers of implementing custom authentication mechanisms without thorough security review. The flaw represents a failure in security by design principles where the plugin's developers chose to implement an alternative authentication method rather than leveraging the robust security infrastructure already available within WordPress. Regular security audits and proper code reviews should be implemented to prevent similar issues in other custom implementations and third-party plugins.
The remediation process requires immediate patching of the affected plugin, but also necessitates ongoing monitoring for signs of exploitation attempts. Organizations should implement automated systems to detect unusual authentication patterns and establish incident response procedures specific to credential compromise scenarios. Regular security assessments should include verification that all plugins properly integrate with WordPress's authentication infrastructure rather than implementing independent solutions that may introduce security vulnerabilities.