CVE-2026-0687: Meta-box GalleryMeta Auth Bypass Flaw

CVE-2026-0687 Overview

The Meta-box GalleryMeta plugin for WordPress contains a Missing Authorization vulnerability (CWE-862) that allows unauthorized modification of data. The vulnerability exists due to a missing capability check on the mb_gallery custom post type in all versions up to and including 3.0.1. This security flaw enables authenticated attackers with Author-level access or above to create and publish galleries without proper authorization.

Critical Impact

Authenticated users with Author privileges can bypass authorization controls to create and publish galleries, potentially leading to content manipulation and unauthorized data modifications on affected WordPress sites.

Affected Products

• Meta-box GalleryMeta plugin for WordPress versions up to and including 3.0.1

Discovery Timeline

• 2026-01-24 - CVE CVE-2026-0687 published to NVD
• 2026-01-26 - Last updated in NVD database

Technical Details for CVE-2026-0687

Vulnerability Analysis

This vulnerability stems from improper access control implementation within the Meta-box GalleryMeta plugin. The plugin fails to implement proper capability checks when users interact with the mb_gallery custom post type. In WordPress, custom post types should enforce capability mappings that restrict which user roles can create, edit, or publish content. Without these checks, users with lower-privilege roles (such as Authors) can perform actions typically reserved for higher-privilege roles (such as Editors or Administrators).

The flaw resides in the post type registration and gallery metabox handling code. When the custom post type is registered, it does not properly map capabilities to restrict access, allowing any authenticated user with Author-level access to create and publish gallery content without authorization.

Root Cause

The root cause is a missing capability check (CWE-862: Missing Authorization) in the custom post type registration within the plugin. The mb_gallery post type does not enforce proper capability requirements, meaning the plugin fails to verify whether the current user has sufficient permissions before allowing gallery creation and publication. This is a common WordPress plugin security issue where developers neglect to implement capability_type parameters or custom capability mappings when registering custom post types.

Attack Vector

An attacker needs to be authenticated with at least Author-level access to exploit this vulnerability. The attack is conducted over the network through standard WordPress administrative interfaces. The attacker can:

1. Log in to the WordPress site with Author credentials
2. Access the gallery creation functionality through the WordPress admin panel
3. Create and publish galleries without proper authorization checks
4. Potentially manipulate site content or inject malicious gallery items

The vulnerability requires no user interaction beyond the attacker's own actions, and the complexity is low as it only requires standard plugin functionality access.

Detection Methods for CVE-2026-0687

Indicators of Compromise

• Unexpected gallery posts created by users with Author-level roles
• Gallery content published without editorial approval workflow
• Audit logs showing gallery post creation from non-privileged user accounts
• Unusual activity patterns in WordPress admin related to gallery management

Detection Strategies

• Review WordPress user activity logs for Author-level users creating gallery content
• Implement WordPress security plugins that monitor capability bypass attempts
• Enable detailed logging for custom post type operations
• Audit mb_gallery post type entries for unauthorized creations

Monitoring Recommendations

• Deploy WordPress security monitoring solutions to track user privilege usage
• Configure alerts for gallery post creation events from non-Administrator accounts
• Regularly review the wp_posts table for entries with post_type='mb_gallery' and verify author permissions
• Implement SentinelOne Singularity XDR for comprehensive endpoint monitoring and WordPress application behavior analysis

How to Mitigate CVE-2026-0687

Immediate Actions Required

• Update the Meta-box GalleryMeta plugin to a patched version when available
• Audit existing gallery posts for unauthorized content
• Review and restrict Author-level user accounts on affected WordPress installations
• Consider temporarily disabling the plugin until a patch is released

Patch Information

A patch addressing this vulnerability has not been explicitly confirmed in the available data. Site administrators should monitor the Wordfence Vulnerability Report for updates on remediation status. The vulnerable code can be reviewed at the plugin post type registration and gallery metabox handling references.

Workarounds

• Restrict Author-level access on sites using this plugin until patched
• Use a WordPress capability management plugin to manually enforce stricter permissions on the mb_gallery post type
• Implement server-side access controls to restrict plugin functionality to trusted administrators only
• Consider using alternative gallery plugins with proper authorization controls

# WordPress wp-config.php - Restrict plugin access temporarily
# Add to wp-config.php to disable plugin loading for non-admins
# Note: This is a temporary workaround and may break functionality

# Check with security team before implementing
# define('DISALLOW_FILE_MODS', true);