CVE-2026-104399: StylemixThemes Motors Data Disclosure Flaw

CVE-2026-104399 Overview

CVE-2026-104399 is an information disclosure vulnerability in the StylemixThemes Motors plugin for WordPress, a car dealership and classified listings solution. The flaw falls under [CWE-201: Insertion of Sensitive Information Into Sent Data] and allows unauthenticated attackers to retrieve embedded sensitive data from server responses over the network. The issue affects all Motors plugin versions from the initial release through 1.4.124. Exploitation requires no authentication, no user interaction, and no special privileges, making the data retrievable by any remote actor who can reach the WordPress site.

Critical Impact
Unauthenticated remote attackers can harvest sensitive data embedded in responses from vulnerable Motors plugin instances, enabling reconnaissance and follow-on attacks against WordPress sites.

Affected Products

StylemixThemes Motors plugin for WordPress
All versions from initial release through 1.4.124
WordPress sites running the Motors Car Dealership & Classified Listings plugin

Discovery Timeline

2026-10-06 - CVE-2026-104399 published to NVD
2026-10-06 - Last updated in NVD database

Technical Details for CVE-2026-104399

Vulnerability Analysis

The vulnerability is categorized as Insertion of Sensitive Information Into Sent Data [CWE-201]. The Motors plugin embeds sensitive information in data that is sent to clients during normal operation. Because the data is included in responses accessible without authentication, any remote user can retrieve it by issuing standard HTTP requests to the affected endpoints.

The scope is limited to confidentiality. The vulnerability does not permit modification of data or disruption of service, but the disclosed information may include values that assist attackers in profiling the site, enumerating objects, or preparing targeted attacks against the WordPress backend.

Further technical specifics are documented in the Patchstack Vulnerability Report.

Root Cause

The plugin fails to strip or restrict sensitive fields before including them in HTTP responses returned to unauthenticated clients. Server-side data intended for privileged contexts is serialized into output that is reachable without session validation or capability checks.

Attack Vector

The attack vector is network-based. An attacker sends crafted or routine HTTP requests to a WordPress site running a vulnerable Motors plugin build and parses the response to extract embedded sensitive values. No authentication, user interaction, or elevated privileges are required.

No verified public proof-of-concept code is available for this issue. Refer to the Patchstack advisory for additional detail on the affected endpoints and response fields.

Detection Methods for CVE-2026-104399

Indicators of Compromise

Repeated unauthenticated HTTP GET requests to Motors plugin REST or AJAX endpoints from a single source IP.
Response payloads containing fields that should be restricted to authenticated or administrative contexts.
Anomalous scraping patterns targeting /wp-json/ paths registered by the Motors plugin.

Detection Strategies

Inspect WordPress access logs for high-volume requests against Motors plugin endpoints and correlate with user-agent anomalies.
Deploy response-body inspection on the web application firewall (WAF) to flag sensitive field names leaving the server to unauthenticated callers.
Audit the installed Motors plugin version against 1.4.124 or lower across all managed WordPress sites.

Monitoring Recommendations

Baseline normal request rates to Motors REST endpoints and alert on deviations.
Forward WordPress and reverse-proxy logs to a centralized analytics platform for correlation and retention.
Monitor outbound data flows for unusual scraping behavior tied to classified listings or dealership metadata.

How to Mitigate CVE-2026-104399

Immediate Actions Required

Identify all WordPress sites running the Motors plugin and confirm installed versions.
Update the Motors plugin to a release later than 1.4.124 once the vendor publishes a fixed version.
Restrict access to Motors plugin REST and AJAX endpoints with a WAF rule until patching is complete.
Review recent access logs for signs of large-scale enumeration against affected endpoints.

Patch Information

Refer to the Patchstack Vulnerability Report for the latest patch status. The advisory lists affected versions through 1.4.124. Apply the vendor-supplied update as soon as it becomes available via the WordPress plugin repository.

Workarounds

Temporarily disable the Motors plugin if a patched version is not yet available and the dealership functionality is non-critical.
Add WAF rules that block or sanitize responses from vulnerable endpoints exposing sensitive fields.
Place the WordPress admin and plugin endpoints behind IP allowlists where business requirements permit.

bash

# Example WAF rule concept to block unauthenticated access to Motors REST endpoints
# Replace <motors-endpoint> with the specific path identified in the Patchstack advisory
location ~ ^/wp-json/<motors-endpoint>/ {
    if ($http_cookie !~ "wordpress_logged_in") {
        return 403;
    }
}