CVE-2025-52122 is a Server-Side Template Injection (SSTI) vulnerability affecting the Freeform plugin versions 5.0.0 up to but not including 5.10.16 for CraftCMS. Freeform is a widely used form-building plugin that allows users to create and manage forms within the CraftCMS content management system. The vulnerability arises because the plugin improperly handles user input in the form submission title field, which is processed within server-side templates without adequate sanitization or validation. This flaw enables any user with permissions to edit a form submission title to inject arbitrary template code that the server will execute. As a result, an attacker can execute arbitrary code on the server hosting the CraftCMS instance, potentially leading to full system compromise. The vulnerability does not require external unauthenticated access; it requires the attacker to have editing rights on form submissions, which may be granted to certain user roles within an organization. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. However, the nature of SSTI vulnerabilities is inherently dangerous because they allow direct code execution on the server, bypassing many traditional security controls. The lack of a patch link suggests that a fix may be pending or that users must upgrade to version 5.10.16 or later to remediate the issue. Organizations using affected versions of Freeform should consider this a critical security risk due to the potential for arbitrary code execution and subsequent full server compromise.

For European organizations, the impact of this vulnerability can be severe. CraftCMS is popular among European businesses, government agencies, and media companies for managing digital content and forms. An attacker exploiting this SSTI vulnerability could gain unauthorized access to sensitive data, manipulate or delete content, disrupt website availability, or use the compromised server as a foothold for lateral movement within the network. This could lead to data breaches involving personal data protected under GDPR, resulting in regulatory fines and reputational damage. Additionally, compromised web servers could be used to distribute malware or conduct further attacks against European infrastructure. The requirement for authenticated access limits the attack surface to users with form editing privileges, but insider threats or compromised user accounts could still enable exploitation. Given the criticality of web presence and digital services in Europe, successful exploitation could disrupt business operations and erode customer trust.

To mitigate this vulnerability, European organizations should immediately identify all CraftCMS instances using the Freeform plugin versions between 5.0.0 and 5.10.15 inclusive. They should upgrade the plugin to version 5.10.16 or later, where the vulnerability is patched. Until the upgrade is applied, organizations should restrict form editing permissions to the minimum number of trusted users and implement strict access controls and monitoring on accounts with such privileges. Web application firewalls (WAFs) can be tuned to detect and block suspicious template injection patterns in form submission titles. Additionally, organizations should audit logs for unusual activity related to form editing and template processing. Employing runtime application self-protection (RASP) tools can help detect and prevent exploitation attempts in real time. Finally, organizations should review their incident response plans to prepare for potential exploitation scenarios involving arbitrary code execution on web servers.