High severity · published Oct 15, 2026
CVE-2026-18548
Groundhogg <= 4.5.14 - Unauthenticated Stored Cross-Site Scripting via 'ref' Parameter
7.2
CVSS
0.3%
EPSS
No
On KEV
Description
The Groundhogg — CRM, Newsletters, and Marketing Automation plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'ref' parameter in all versions up to, and including, 4.5.14 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GC
Groundhogg — CRM, Newsletters, and Marketing Automation · trainingbusinesspros
through 4.5.14 · source: vendor
Affected product
GC
Groundhogg — CRM, Newsletters, and Marketing Automation
trainingbusinesspros
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-18548
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-18548
github.com
https://github.com/groundhoggwp/groundhogg/commit/8a6fe60e751e
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/groundhogg/tags/4.5.15/assets/js/admin/contacts/contact-editor.js#L848
www.wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/791ee926-edd9-4615-9a46-1d8836938fd9?source=cve
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