CVE-2026-105876: Modula Image Gallery Authorization Flaw

CVE-2026-105876 Overview

CVE-2026-105876 is a Missing Authorization vulnerability [CWE-862] in the WP Chill Modula Image Gallery WordPress plugin (modula-best-grid-gallery). The flaw allows unauthenticated attackers to retrieve embedded sensitive data from affected sites over the network. The issue affects all versions of Modula Image Gallery up to and including 3.0.11.

Because the vulnerable endpoints lack proper authorization checks, exploitation does not require user interaction or valid credentials. Attackers can harvest data that should be restricted to authenticated or privileged users.

Critical Impact
Unauthenticated remote attackers can access embedded sensitive data in Modula Image Gallery versions through 3.0.11 without authentication or user interaction.

Affected Products

WP Chill Modula Image Gallery (modula-best-grid-gallery) — versions through 3.0.11
WordPress sites running the vulnerable plugin
Any deployment exposing the plugin's unauthenticated endpoints to the internet

Discovery Timeline

2026-10-07 - CVE-2026-105876 published to the National Vulnerability Database
2026-10-07 - Last updated in NVD database

Technical Details for CVE-2026-105876

Vulnerability Analysis

The vulnerability stems from missing authorization controls in the Modula Image Gallery plugin. One or more plugin endpoints fail to validate whether the requesting user has permission to access the requested resource. As a result, unauthenticated requests return data that should be protected.

The impact is limited to confidentiality. Integrity and availability of the target site are not affected. However, exposed data may include configuration, metadata, or embedded content intended for restricted audiences.

For technical details, see the Patchstack Vulnerability Disclosure.

Root Cause

The root cause is a failure to perform capability or nonce checks before returning data from the affected plugin endpoints. In WordPress plugins, this typically occurs when AJAX actions, REST routes, or admin-ajax handlers omit calls to functions such as current_user_can() or check_ajax_referer(). The handler executes and returns sensitive data regardless of the caller's identity.

Attack Vector

An attacker sends crafted HTTP requests to the vulnerable plugin endpoint on any WordPress site running Modula Image Gallery 3.0.11 or earlier. No authentication, privileges, or user interaction are required. The server processes the request and returns embedded sensitive data in the response body.

See the Patchstack advisory for endpoint-specific details.

Detection Methods for CVE-2026-105876

Indicators of Compromise

Unauthenticated HTTP requests to Modula-related endpoints under /wp-admin/admin-ajax.php or /wp-json/ referencing modula actions or routes
Anomalous response sizes from plugin endpoints indicating bulk data retrieval
Repeated access from a single source IP enumerating gallery or configuration data

Detection Strategies

Review web server access logs for unauthenticated requests to Modula plugin endpoints returning HTTP 200 with non-trivial response payloads
Correlate requests referencing the modula-best-grid-gallery plugin path with absent authentication cookies or nonces
Deploy a Web Application Firewall rule to flag requests targeting known vulnerable Modula actions

Monitoring Recommendations

Alert on spikes in traffic to WordPress AJAX or REST endpoints associated with the Modula plugin
Monitor outbound data volume from WordPress hosts to identify large unauthenticated responses
Track plugin inventory across managed WordPress sites to confirm versions in use

How to Mitigate CVE-2026-105876

Immediate Actions Required

Identify all WordPress installations running modula-best-grid-gallery version 3.0.11 or earlier
Update the plugin to a patched version as published by WP Chill once available
Restrict public access to WordPress AJAX and REST endpoints where feasible
Rotate any credentials or secrets that may have been exposed through embedded plugin data

Patch Information

At the time of publication, the vulnerability affects Modula Image Gallery through 3.0.11. Administrators should consult the Patchstack advisory and the WordPress plugin repository for the fixed release and upgrade immediately once available.

Workarounds

Deploy WAF rules blocking unauthenticated requests to Modula plugin endpoints until a patch is applied
Temporarily deactivate the Modula Image Gallery plugin if upgrading is not immediately possible
Restrict access to /wp-admin/admin-ajax.php and /wp-json/ from untrusted networks using host- or edge-level controls

bash

# Example nginx rule to block unauthenticated access to Modula endpoints
location ~* /wp-admin/admin-ajax\.php {
    if ($arg_action ~* "modula") {
        return 403;
    }
}