CVE-2025-12826 Overview
CVE-2025-12826 is an authorization bypass vulnerability in the Custom Post Type UI plugin for WordPress. The flaw affects all versions up to and including 1.18.0. The plugin fails to verify user capabilities in the cptui_process_post_type function before executing sensitive actions. Authenticated attackers holding subscriber-level access or above can add, edit, or delete custom post types in limited situations. The weakness is categorized as Missing Authorization [CWE-862] and stems from broken access control in a widely deployed WordPress extension.
Critical Impact
Low-privileged WordPress users can modify custom post type configurations, potentially disrupting site content structure and taxonomy behavior.
Affected Products
- Custom Post Type UI plugin for WordPress
- All versions up to and including 1.18.0
- WordPress installations with subscriber-level or higher user registration enabled
Discovery Timeline
- 2025-12-04 - CVE-2025-12826 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-12826
Vulnerability Analysis
The vulnerability resides in the cptui_process_post_type function within the Custom Post Type UI plugin. This function processes requests to create, modify, or delete custom post types. The function does not include a capability check to confirm that the requesting user holds administrative privileges. As a result, any authenticated user with at least subscriber-level access can invoke the function.
The plugin's post type management logic assumes callers are administrators without enforcing that assumption in code. This is a classic Missing Authorization weakness [CWE-862] where authentication is verified but authorization is not.
Root Cause
The root cause is the absence of a current_user_can() capability check inside the cptui_process_post_type handler. WordPress requires plugin authors to explicitly verify that the requesting user holds an appropriate capability such as manage_options before executing privileged actions. The Custom Post Type UI plugin omitted this check on the affected code path, delegating trust to authentication alone.
Attack Vector
An attacker first obtains a subscriber account, either through open registration or credential compromise. The attacker then submits a crafted request to the plugin endpoint that triggers cptui_process_post_type. The endpoint accepts parameters that specify whether to add, edit, or delete a custom post type. Successful exploitation modifies the site's post type registry without administrator approval.
Exploitation requires specific site conditions, which limits reliability. Site owners who have registered custom post types are exposed to configuration tampering, which can break custom templates, taxonomy relationships, and content queries. Refer to the Wordfence Vulnerability Report and the GitHub Commit Update for technical details of the patch.
Detection Methods for CVE-2025-12826
Indicators of Compromise
- Unexpected creation, modification, or deletion of custom post types in the WordPress admin dashboard
- POST requests to admin.php or admin-ajax.php referencing cptui actions originating from subscriber accounts
- Changes to the cptui_post_types option in the WordPress wp_options table
- Audit log entries showing post type schema changes without corresponding administrator sessions
Detection Strategies
- Monitor WordPress request logs for cptui_process_post_type invocations correlated with non-administrator session cookies
- Enable a WordPress activity log plugin to record option updates and post type registrations
- Alert on modifications to plugin-managed options performed by users lacking the manage_options capability
Monitoring Recommendations
- Review the running Custom Post Type UI version across all managed WordPress sites and flag any at 1.18.0 or earlier
- Track HTTP requests targeting the plugin's admin endpoints for anomalous frequency or unexpected user roles
- Baseline the site's registered custom post types and alert on deviations
How to Mitigate CVE-2025-12826
Immediate Actions Required
- Update the Custom Post Type UI plugin to the version published after 1.18.0 that addresses the missing capability check
- Audit existing WordPress user accounts and remove unused subscriber-level accounts
- Review custom post type definitions to confirm they match the intended site configuration
Patch Information
The vendor addressed this issue in the commit referenced by the GitHub Commit Update. The patch introduces a capability check in the cptui_process_post_type function to ensure only users with administrative privileges can process post type actions. Site operators should apply the patched release through the WordPress plugin updater.
Workarounds
- Disable open user registration to prevent untrusted parties from obtaining subscriber accounts
- Restrict access to wp-admin endpoints using a web application firewall rule that blocks cptui parameters from non-administrator sessions
- Temporarily deactivate the Custom Post Type UI plugin if patching is not immediately feasible
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
