CVE-2025-9821: 
PHP vulnerability analysis and mitigation

CVE-2025-9821 is a Server-Side Request Forgery (SSRF) vulnerability discovered in Mautic's webhook functionality. The vulnerability affects Mautic versions >= 4.4.0, < 4.4.17, >= 5.0.0-alpha, < 5.2.8, and >= 6.0.0-alpha, < 6.0.5. The issue was disclosed on September 3, 2025, and allows users with webhook permissions to conduct SSRF attacks via webhooks (Mautic Advisory).

The vulnerability stems from insufficient validation of webhook destinations when sending webhooks. Users with webhook permissions can potentially access and interact with internal services through SSRF attacks. The vulnerability has been assigned a CVSS v3.1 base score of 2.7 (Low) with the vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N, indicating network attack vector, low attack complexity, high privileges required, no user interaction needed, unchanged scope, and low confidentiality impact (Mautic Advisory).

The primary impact of this vulnerability is the potential bypass of firewalls to interact with internal services. Additionally, if users have permission to view webhook logs, they can access (partial) request responses from the SSRF attempts. This could lead to unauthorized access to internal resources and potential information disclosure (Mautic Advisory).

The vulnerability has been patched in Mautic versions 4.4.17, 5.2.8, and 6.0.5. Organizations are advised to upgrade to these patched versions to mitigate the risk. For additional protection against SSRF attacks, organizations can refer to the OWASP Server Side Request Forgery Prevention Cheat Sheet (Mautic Advisory).