This vulnerability (CVE-2024-35668) involves improper neutralization of input in Brevo's Newsletter, SMTP, Email marketing, and Subscribe forms by Sendinblue, leading to reflected Cross-site Scripting (CWE-79). It affects versions up to 3.1.77. The CVSS 3.1 base score is 7.1, indicating high severity, with attack vector network, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality, integrity, and availability. No vendor advisory or patch is currently available, and the product is not a cloud service, so remediation depends on vendor updates or user mitigation.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the affected web application, potentially leading to information disclosure, session hijacking, or other impacts on confidentiality, integrity, and availability. The CVSS score of 7.1 reflects these risks. However, no known exploits are currently reported in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider implementing input validation and output encoding on their own deployment of the affected forms to mitigate reflected XSS risks. Monitor vendor channels for updates regarding patches or official mitigations.