CVE-2026-6831: WordPress Contact Form 7 DB Auth Bypass

CVE-2026-6831 Overview

CVE-2026-6831 affects the Advanced Contact form 7 DB plugin for WordPress in all versions up to and including 2.0.9. The plugin fails to verify user authorization before allowing access to Contact Form 7 submission data through the acf7db shortcode. Authenticated users with Contributor-level access or higher can read all form submission data stored by the plugin. The issue is classified as Missing Authorization [CWE-862] and stems from improper access control on shortcode execution.

Critical Impact
Authenticated attackers with Contributor privileges can exfiltrate all Contact Form 7 submission records, exposing personally identifiable information collected through website forms.

Affected Products

Advanced Contact form 7 DB plugin for WordPress, versions up to and including 2.0.9
WordPress sites permitting Contributor-level or higher registration
Sites using the acf7db shortcode functionality

Discovery Timeline

2026-09-23 - CVE-2026-6831 published to the National Vulnerability Database
2026-09-23 - Last updated in NVD database

Technical Details for CVE-2026-6831

Vulnerability Analysis

The Advanced Contact form 7 DB plugin stores submissions from Contact Form 7 forms into the WordPress database and exposes retrieval functionality through the acf7db shortcode. The shortcode handler does not perform a capability check before returning submission records. Any authenticated user permitted to author content, which in WordPress includes the Contributor role, can insert the shortcode into a draft post or preview and receive the rendered output containing stored form data.

WordPress evaluates shortcodes when a post is previewed or rendered, so the attacker does not need to publish content. Because the plugin trusts the calling context rather than validating the user's role or capability against the sensitivity of the data, submission records intended for administrators are disclosed to lower-privileged accounts.

Submission records typically contain names, email addresses, message bodies, IP addresses, and any custom fields collected by Contact Form 7. Exposure of these records may trigger data breach notification obligations under regulations such as GDPR and CCPA.

Root Cause

The root cause is a missing current_user_can() authorization check within the shortcode callback. The plugin relies on the assumption that only administrators can insert or execute the shortcode, but WordPress does not restrict shortcode processing by role. See the WordPress Plugin Changeset for the applied fix.

Attack Vector

An attacker authenticates to a target WordPress site using a Contributor, Author, Editor, or Administrator account. The attacker creates a new post or page draft and inserts the [acf7db] shortcode with parameters that reference stored form submissions. Using the WordPress preview function, the attacker renders the draft and reads the returned submission data. No published content is produced, and the activity leaves limited forensic traces beyond standard post revision history.

The vulnerability is exploitable over the network and requires only low-privilege authenticated access. See the Wordfence Vulnerability Analysis for additional technical context.

Detection Methods for CVE-2026-6831

Indicators of Compromise

Post revisions or drafts authored by low-privileged users containing the [acf7db] shortcode
Unusual POST requests to wp-admin/post.php or wp-admin/admin-ajax.php from Contributor accounts followed by preview requests
Access log entries showing preview=true requests to draft posts authored by non-administrator users

Detection Strategies

Query the wp_posts table for post content containing the string acf7db where post_author is not an administrator
Review WordPress activity logs for shortcode insertions by users below Editor role
Correlate outbound data volume from preview requests against baselines for Contributor accounts

Monitoring Recommendations

Enable WordPress audit logging to record post creation, revision, and preview events with user attribution
Alert on any Contributor or Author account that previews posts containing plugin shortcodes handling stored data
Track plugin version inventory across managed WordPress sites to identify installations still running 2.0.9 or earlier

How to Mitigate CVE-2026-6831

Immediate Actions Required

Update the Advanced Contact form 7 DB plugin to version 2.1.2 or later on all WordPress installations
Audit user accounts and remove or downgrade unnecessary Contributor, Author, and Editor accounts
Review recent post revisions and drafts for unauthorized use of the acf7db shortcode

Patch Information

The vendor released a fix in version 2.1.2 that adds authorization checks to the shortcode handler. The code changes are documented in the WordPress Plugin Changeset between tags 2.1.1 and 2.1.2. Administrators should apply the update through the WordPress plugin dashboard or via wp-cli.

Workarounds

Deactivate the Advanced Contact form 7 DB plugin until version 2.1.2 or later can be installed
Restrict user registration and require administrator approval for new accounts requesting Contributor or higher roles
Use a Web Application Firewall rule to block requests containing the acf7db shortcode from non-administrator sessions

bash

# Update the plugin using wp-cli
wp plugin update advanced-cf7-db --version=2.1.2

# Verify installed version
wp plugin get advanced-cf7-db --field=version

# Audit posts referencing the vulnerable shortcode
wp db query "SELECT ID, post_author, post_status FROM wp_posts WHERE post_content LIKE '%[acf7db%';"