What's the vulnerability?
The Groundhogg — CRM, Newsletters, and Marketing Automation plugin for WordPress is vulnerable to Privilege Escalation via Contact Identity Rebinding in all versions up to, and including, 4.9 The vulnerability exists because the `create_contact` function in the v3 REST endpoint (`POST /gh/v3/contacts`) is gated solely by the `add_contacts` capability and forwards the full request payload — including the security-bearing `user_id` column — into the upsert path of `Contacts_DB::add()`, which bypasses the ownership guard that `Contacts_DB::update()` enforces, allowing an attacker to rebind any existing contact record to an arbitrary WordPress user ID. This makes it possible for authenticated attackers with Sales Representative-level access and above to upsert their own contact row to point to an Administrator's user ID, then invoke the v4 email-test endpoint (`POST /gh/v4/emails/test`) — also accessible to the Sales Representative role via the `send_emails` capability — to generate an `{auto_login_url}` one-time permissions key bound to the rebound contact, and consume that link to call `wp_set_auth_cookie()` and gain a fully authenticated session as the WordPress Administrator.
Business impact & how R4IM helps
This advisory is on our active-exploitation watchlist. Attackers are using it for initial access, privilege escalation or lateral movement in real-world intrusions. R4IM's offensive security and SOC teams already have detections, exploit replicas and remediation playbooks for this issue.
Targeted vulnerability assessment to confirm which of your assets are actually exploitable — not just theoretically affected.
Our pentesters chain this CVE into realistic attack paths so you see business impact, not just a scan finding.
If the affected product is internet-facing, our AppSec team will harden it against this and related OWASP-class issues.
Continuous monitoring with custom detections for this CVE deployed across your endpoints, identity and cloud.
Recommended remediation
- Inventory all assets running the affected vendor and product, including shadow IT and third-party hosted instances.
- Apply the vendor patch or mitigation referenced in the advisories below. Where no patch exists, isolate the asset or restrict network exposure.
- Hunt for indicators of prior compromise — exploitation of this class of bug often predates public disclosure.
- Deploy detections for the exploit primitives (network signature, EDR rule, WAF rule) and re-test after remediation.
Need help executing these steps? Our team typically completes validation and remediation within a single patch cycle. Request remediation support →
Vendor & research references
- https://plugins.trac.wordpress.org/browser/groundhogg/tags/4.8.3/api/v3/contacts-api.php#L373 · security@wordfence.com
- https://plugins.trac.wordpress.org/browser/groundhogg/tags/4.8.3/api/v4/emails-api.php#L571 · security@wordfence.com
- https://plugins.trac.wordpress.org/browser/groundhogg/tags/4.8.3/db/contacts.php#L205 · security@wordfence.com
- https://plugins.trac.wordpress.org/browser/groundhogg/tags/4.8.3/includes/main-roles.php#L532 · security@wordfence.com
- https://plugins.trac.wordpress.org/browser/groundhogg/tags/4.8.3/includes/replacements.php#L2280 · security@wordfence.com
- https://plugins.trac.wordpress.org/browser/groundhogg/tags/4.8.3/includes/rewrites.php#L460 · security@wordfence.com
- https://plugins.trac.wordpress.org/changeset/3724910/groundhogg/trunk/api/v3/contacts-api.php · security@wordfence.com
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3724910%40groundhogg%2Ftags%2F4.9.1&old=3724058%40groundhogg%2Ftags%2F4.9 · security@wordfence.com
- https://www.wordfence.com/threat-intel/vulnerabilities/id/557306b7-7b66-465e-8d4d-ebae5b1577c9?source=cve · security@wordfence.com
