CVE-2026-74925: MultiVendorX WordPress Privilege Escalation

CVE-2026-74925 Overview

CVE-2026-74925 is a privilege escalation vulnerability in the MultiVendorX WordPress plugin versions before 5.0.16. The plugin fails to restrict access to its role and capability settings endpoint. Users assigned the vendor role can modify capability mappings and grant themselves administrator-level capabilities. This allows a low-trust vendor account to take over the entire WordPress site. The flaw is classified as [CWE-269] Improper Privilege Management. Site owners running multi-vendor marketplaces on WordPress are directly exposed, since vendor onboarding is often open or lightly gated.

Critical Impact
An authenticated vendor user can escalate to administrator and achieve full site takeover, including content modification, user manipulation, and code execution through plugin or theme installation.

Affected Products

MultiVendorX WordPress plugin versions prior to 5.0.16
WordPress sites operating a multi-vendor marketplace using MultiVendorX
Any vendor-role account provisioned on a vulnerable installation

Discovery Timeline

2026-09-11 - CVE-2026-74925 published to the National Vulnerability Database (NVD)
2026-09-11 - Last updated in NVD database

Technical Details for CVE-2026-74925

Vulnerability Analysis

The MultiVendorX plugin exposes an administrative settings interface used to define which WordPress capabilities are attached to plugin-managed roles, including the vendor role. The handler responsible for saving those role and capability configurations does not verify whether the requesting user holds administrative privileges. It relies on authentication alone rather than an authorization check.

A vendor-role user, once logged in, can submit a crafted request to that settings endpoint and rewrite the capability list associated with their own role. By assigning capabilities such as manage_options, edit_users, install_plugins, or unfiltered_html, the attacker converts a limited vendor account into an effective administrator without changing role labels.

Because capability grants are persistent in the WordPress options table, the escalation survives session expiration and does not require ongoing exploitation. Full technical details are documented in the WPScan Vulnerability Advisory.

Root Cause

The root cause is missing authorization enforcement on a privileged settings action. The plugin authenticates the request and confirms the user is logged in, but does not call a capability check such as current_user_can( 'manage_options' ) before persisting role and capability changes. This is a textbook [CWE-269] Improper Privilege Management defect.

Attack Vector

Exploitation is remote and requires an authenticated session with the vendor role. The attacker sends an HTTP POST request to the plugin's role and capability settings handler, supplying a modified capability set for the vendor role. After submission, the attacker refreshes their session or re-authenticates and gains administrator-level control of the site.

No verified public exploit code is available. Refer to the WPScan Vulnerability Advisory for reproduction details.

Detection Methods for CVE-2026-74925

Indicators of Compromise

Unexpected modifications to WordPress role definitions stored under the wp_user_roles option in wp_options.
Vendor-role accounts that suddenly hold capabilities such as manage_options, edit_users, install_plugins, or promote_users.
Plugin, theme, or user administration actions performed by accounts originally provisioned as vendors.
New administrator accounts created shortly after a vendor account authenticated.

Detection Strategies

Audit the wp_user_roles option and compare current vendor capabilities against a known-good baseline from a clean MultiVendorX install.
Review web server access logs for POST requests to MultiVendorX settings endpoints originating from non-administrator sessions.
Correlate WordPress user activity logs to identify capability escalation events followed by privileged actions such as plugin installation or user creation.

Monitoring Recommendations

Enable a WordPress audit logging plugin to record role and capability changes in real time.
Alert on any write to wp_user_roles outside of a scheduled maintenance window.
Monitor for administrator-only actions performed by session identifiers previously bound to vendor accounts.

How to Mitigate CVE-2026-74925

Immediate Actions Required

Upgrade MultiVendorX to version 5.0.16 or later on all affected WordPress sites.
Review every vendor-role account and reset credentials for any account that cannot be verified as legitimate.
Inspect the wp_user_roles option and restore vendor capabilities to the plugin defaults if tampering is detected.
Rotate WordPress secret keys in wp-config.php and force re-authentication for all users if compromise is suspected.

Patch Information

The vendor has released MultiVendorX 5.0.16, which adds the missing authorization checks on the role and capability settings handler. Site administrators should update through the WordPress plugin dashboard or via WP-CLI. See the WPScan Vulnerability Advisory for confirmation of the fixed version.

Workarounds

Temporarily disable the MultiVendorX plugin until the patched version can be deployed.
Restrict vendor registration and require manual approval to reduce the pool of accounts that can attempt exploitation.
Place the WordPress admin surface behind an authenticated reverse proxy or IP allowlist to limit request access to the vulnerable endpoint.

bash

# Update MultiVendorX using WP-CLI
wp plugin update dc-woocommerce-multi-vendor --version=5.0.16

# Verify the installed version
wp plugin get dc-woocommerce-multi-vendor --field=version

# Inspect current vendor role capabilities
wp role list
wp cap list vendor