CVE-2025-26867: Themes4WP Bulk Auth Bypass Vulnerability

CVE-2025-26867 Overview

CVE-2025-26867 is a Missing Authorization vulnerability [CWE-862] in the Themes4WP Bulk WordPress theme. The flaw affects all versions up to and including 1.0.11. It allows unauthenticated network attackers to access functionality that is not properly constrained by access control lists (ACLs). Successful exploitation results in limited integrity impact on the affected WordPress site.

The issue is tracked by Patchstack and stems from broken access control in theme-provided endpoints. No authentication or user interaction is required to invoke the exposed functionality.

Critical Impact
Unauthenticated attackers can invoke Bulk theme functions that should be restricted, enabling limited unauthorized modification of WordPress site data.

Affected Products

Themes4WP Bulk WordPress theme versions n/a through 1.0.11
WordPress sites using the vulnerable Bulk theme
Any deployment exposing the theme's front-end or AJAX endpoints to the internet

Discovery Timeline

2025-05-19 - CVE-2025-26867 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-26867

Vulnerability Analysis

The Bulk theme exposes one or more endpoints that fail to verify the requester's privileges before executing sensitive operations. Access control checks such as current_user_can() or nonce verification via check_ajax_referer() are either missing or incorrectly applied. As a result, callers bypass WordPress role-based restrictions.

The vulnerability is categorized as Broken Access Control [CWE-862]. Attackers reach the exposed handler over the network without credentials. The impact is limited to integrity, meaning attackers can modify a subset of theme-managed data but cannot directly read sensitive content or take the site offline through this flaw.

The EPSS probability for exploitation activity in the next 30 days is low based on Patchstack's advisory data. However, WordPress theme flaws of this class are routinely swept by automated scanners once details become public.

Root Cause

The root cause is missing authorization enforcement on theme-registered actions. WordPress themes that register AJAX hooks with both wp_ajax_ and wp_ajax_nopriv_ prefixes, or that expose custom REST routes, must independently validate capabilities. The Bulk theme omits this validation on functionality that should be limited to authenticated administrators.

Attack Vector

An unauthenticated attacker sends a crafted HTTP request to the vulnerable WordPress endpoint exposed by the Bulk theme. Because the handler does not check the caller's role, it executes the requested operation. The attack is remote, requires no privileges, and requires no user interaction. Refer to the Patchstack WordPress Vulnerability Advisory for endpoint-specific details.

No public proof-of-concept exploit is currently listed for this CVE.

Detection Methods for CVE-2025-26867

Indicators of Compromise

Unauthenticated POST or GET requests to /wp-admin/admin-ajax.php referencing Bulk theme actions from unknown IP addresses
Modifications to theme options, posts, or metadata without a corresponding authenticated administrator session in wp_users login logs
Unusual User-Agent strings and high-volume requests targeting theme-specific action names

Detection Strategies

Audit web server access logs for requests to theme endpoints that succeed with HTTP 200 but originate from unauthenticated sessions
Correlate WordPress audit logs with web traffic to identify state changes lacking a matching authenticated user event
Deploy a Web Application Firewall (WAF) rule that blocks requests to known Bulk theme action names from anonymous callers

Monitoring Recommendations

Enable a WordPress audit logging plugin to capture option updates, post modifications, and settings changes with attribution
Alert on any change to critical theme options or site settings occurring outside authenticated admin sessions
Monitor for spikes in admin-ajax.php traffic without accompanying authentication cookies

How to Mitigate CVE-2025-26867

Immediate Actions Required

Identify all WordPress instances running the Themes4WP Bulk theme at version 1.0.11 or earlier
Deactivate and replace the Bulk theme until a patched version above 1.0.11 is available and installed
Restrict access to /wp-admin/ and /wp-admin/admin-ajax.php at the WAF or reverse proxy where feasible
Review recent theme option changes, user account additions, and posted content for signs of unauthorized modification

Patch Information

At the time of publication, the Patchstack advisory lists affected versions from n/a through 1.0.11. Site administrators should consult the Patchstack WordPress Vulnerability Advisory for the current fixed version and upgrade guidance from Themes4WP.

Workarounds

Switch to an alternative maintained WordPress theme until a fixed release is confirmed
Deploy virtual patching via a WAF or Patchstack mTuner-style rule that blocks the vulnerable Bulk theme action names
Enforce IP allowlisting on /wp-admin/admin-ajax.php and REST routes exposed by the theme
Require authentication at the reverse proxy layer for all administrative endpoints

bash

# Example nginx snippet to restrict admin-ajax.php to trusted IPs
location = /wp-admin/admin-ajax.php {
    allow 203.0.113.0/24;
    deny all;
    include fastcgi_params;
    fastcgi_pass unix:/run/php/php-fpm.sock;
}