CVE-2026-18594: Contact Form 7 DB Auth Bypass Vulnerability

CVE-2026-18594 Overview

CVE-2026-18594 is an authorization bypass vulnerability in the Advanced Contact Form 7 DB plugin for WordPress. The flaw affects all plugin versions up to and including 2.1.3. The plugin fails to verify that a requesting user is authorized to perform CSV import actions. Authenticated attackers with custom-level access or above can import forged CSV submission records into any Contact Form 7 form managed by the plugin. The issue is categorized as Missing Authorization [CWE-862].

Critical Impact
Authenticated users with low-privilege custom roles can inject arbitrary CSV submission records into Contact Form 7 forms, corrupting stored form data and enabling downstream data-integrity attacks.

Affected Products

Advanced Contact Form 7 DB plugin for WordPress
All versions up to and including 2.1.3
WordPress sites using Contact Form 7 with this plugin installed

Discovery Timeline

2026-09-10 - CVE-2026-18594 published to the National Vulnerability Database (NVD)
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-18594

Vulnerability Analysis

The vulnerability resides in the CSV import functionality of the Advanced Contact Form 7 DB plugin. The plugin exposes an import handler that accepts CSV files and inserts the parsed records as Contact Form 7 submission entries. The affected code paths are located in admin/partials/import_cf7_csv.php and the import_cf7_entry class in admin/partials/import_cf7_entry.class.php.

The handler processes requests without performing a capability check appropriate to the sensitivity of the action. Any authenticated session with custom-level access or above satisfies the plugin's implicit access assumptions and is permitted to submit an import request.

Successful exploitation writes attacker-supplied CSV rows into the plugin's submission database for any Contact Form 7 form managed by the plugin. Confidentiality is not directly affected, but integrity of stored submissions is compromised.

Root Cause

The root cause is missing authorization [CWE-862]. The plugin relies on authentication alone and does not call a WordPress capability check (for example current_user_can()) before executing the import routine. Authorization is therefore not enforced against the privileged action of writing arbitrary records into form submission tables.

Attack Vector

The attack is delivered over the network through the WordPress admin interface. The attacker must hold a valid authenticated session with custom-level privileges or higher. The attacker submits a crafted CSV file to the plugin's import endpoint targeting a chosen Contact Form 7 form ID, and the plugin ingests the rows as legitimate submissions.

No public proof-of-concept exploit or exploitation in the wild has been reported at the time of publication. Technical references are available in the Wordfence Vulnerability Analysis and in the plugin source at import_cf7_csv.php and import_cf7_entry.class.php.

Detection Methods for CVE-2026-18594

Indicators of Compromise

Unexpected Contact Form 7 submission records containing content that does not match legitimate form fields or user activity.
Web server access log entries showing POST requests to Advanced Contact Form 7 DB admin endpoints from low-privilege user sessions.
CSV file uploads to wp-admin originating from accounts holding custom or subscriber-tier roles.
Sudden growth in the plugin's submission table without corresponding front-end form activity.

Detection Strategies

Correlate WordPress audit logs of authenticated sessions against submission-insertion events in the plugin database tables.
Alert on any invocation of the plugin's import_cf7_entry code path by users lacking the manage_options capability.
Baseline the normal ratio of front-end Contact Form 7 submissions to database inserts, and flag deviations.

Monitoring Recommendations

Enable a WordPress activity/audit logging plugin that records file uploads and admin-ajax actions with user role context.
Forward WordPress and web server logs to a centralized SIEM for retention and correlation across users and endpoints.
Review the list of accounts holding custom roles and monitor their administrative activity for privilege abuse.

How to Mitigate CVE-2026-18594

Immediate Actions Required

Inventory all WordPress sites and identify installations of the Advanced Contact Form 7 DB plugin at version 2.1.3 or earlier.
Update the plugin to a version that fixes the missing authorization check as soon as a patched release is available.
Audit Contact Form 7 submission records created since the plugin was installed for injected or forged entries and remove them.
Review and tighten role assignments so that only trusted administrators hold custom roles capable of accessing plugin admin pages.

Patch Information

At the time of publication, no fixed version is listed in the enriched CVE data. Site administrators should monitor the Wordfence advisory and the plugin repository for a release that adds capability checks to the CSV import handler in import_cf7_entry.class.php.

Workarounds

Deactivate the Advanced Contact Form 7 DB plugin until a patched version is installed if CSV import functionality is not required.
Restrict access to the plugin's admin pages using a web application firewall (WAF) rule that blocks requests to the import endpoint from non-administrator sessions.
Remove or downgrade custom roles that grant access to plugin admin screens without a business need.
Enforce multi-factor authentication for all WordPress accounts to raise the cost of gaining the authenticated foothold required for exploitation.

bash

# Example: temporarily deactivate the vulnerable plugin using WP-CLI
wp plugin deactivate advanced-cf7-db

# Verify the plugin status and installed version
wp plugin get advanced-cf7-db --field=version
wp plugin list --status=active | grep advanced-cf7-db