CVE-2026-104385: Groundhogg Data Exposure Vulnerability

CVE-2026-104385 Overview

CVE-2026-104385 is an unauthenticated sensitive data exposure vulnerability in the Groundhogg WordPress plugin, affecting versions up to and including 4.8.3. The flaw allows remote attackers to retrieve sensitive information without authentication over the network. The weakness is categorized under CWE-201: Insertion of Sensitive Information Into Sent Data. Groundhogg is a marketing automation and CRM plugin used by WordPress sites to manage contacts, email campaigns, and funnels, making exposed data particularly valuable to attackers.

Critical Impact
Unauthenticated attackers can access sensitive data stored or processed by the Groundhogg plugin, potentially exposing contact records, campaign details, and other CRM information.

Affected Products

Groundhogg WordPress plugin versions <= 4.8.3
WordPress installations running vulnerable Groundhogg releases
Sites exposing Groundhogg endpoints to untrusted networks

Discovery Timeline

2026-10-06 - CVE-2026-104385 published to NVD
2026-10-06 - Last updated in NVD database

Technical Details for CVE-2026-104385

Vulnerability Analysis

The vulnerability enables unauthenticated attackers to access sensitive information handled by Groundhogg. The issue falls under [CWE-201], which covers cases where sensitive data is inserted into responses or outputs reachable by parties who should not see them. Because the Groundhogg plugin manages contacts and marketing automation data, exposed information may include personally identifiable information (PII) and campaign metadata.

The attack is executed over the network against vulnerable WordPress sites with no privileges or user interaction required. The impact is limited to confidentiality; integrity and availability are not affected.

According to the EPSS model, exploitation probability remains low at the time of publication, but unauthenticated information disclosure flaws in widely deployed WordPress plugins are frequently incorporated into automated scanning toolkits.

Root Cause

The root cause is improper access control on an endpoint or data flow within Groundhogg that returns sensitive information without verifying the requester's identity or authorization. Technical specifics are available in the Patchstack Vulnerability Report.

Attack Vector

An unauthenticated attacker sends crafted HTTP requests to the affected Groundhogg endpoint on a vulnerable WordPress site. The server returns sensitive data that should require authentication or authorization. No user interaction is required, and the attack can be performed remotely from any network location that can reach the site.

No verified public proof-of-concept code is available. Refer to the Patchstack advisory for technical details.

Detection Methods for CVE-2026-104385

Indicators of Compromise

Repeated unauthenticated HTTP requests to Groundhogg REST or AJAX endpoints under /wp-json/ or admin-ajax.php
Anomalous outbound responses from WordPress containing contact, email, or CRM data to unknown IP addresses
Access log entries from scanners probing Groundhogg endpoints across many sites in short time windows

Detection Strategies

Inventory WordPress sites and identify installations running Groundhogg <= 4.8.3
Review HTTP access logs for unauthenticated requests to Groundhogg endpoints returning large or JSON-structured responses
Correlate web server telemetry with WAF alerts for WordPress plugin reconnaissance patterns

Monitoring Recommendations

Forward WordPress and web server logs to a centralized analytics platform for query and correlation
Alert on spikes in request volume to Groundhogg routes from single source IPs
Monitor for user-agent strings associated with WordPress vulnerability scanners

How to Mitigate CVE-2026-104385

Immediate Actions Required

Update Groundhogg to a version later than 4.8.3 as soon as a fixed release is available from the vendor
Audit WordPress sites to confirm plugin inventory and identify exposed installations
Restrict network access to WordPress administrative and plugin endpoints where feasible

Patch Information

Consult the Patchstack Vulnerability Report for the authoritative fixed version and vendor remediation guidance. Apply the vendor-supplied update through the WordPress plugin manager or deployment pipeline.

Workarounds

Deploy a web application firewall (WAF) rule to block unauthenticated requests to the vulnerable Groundhogg endpoints
Temporarily deactivate the Groundhogg plugin on sites that cannot be patched immediately
Rotate any credentials, API keys, or tokens that may have been exposed through the plugin

bash

# Example: list Groundhogg installations and versions across managed WordPress sites
wp plugin list --name=groundhogg --fields=name,status,version --allow-root