This vulnerability in Select-Themes SetSail arises from improper validation or control of filenames used in PHP include or require statements, enabling PHP Local File Inclusion (LFI). An attacker can exploit this to include arbitrary local files on the server, which may lead to disclosure of sensitive information, code execution, or denial of service. The issue affects versions up to and including 1.8. The CVSS 3.1 score of 8.1 reflects network attack vector, high impact on confidentiality, integrity, and availability, but requires high attack complexity and no privileges or user interaction.

Successful exploitation can lead to local file inclusion, allowing attackers to read sensitive files, execute arbitrary code, or disrupt service. The impact is high on confidentiality, integrity, and availability of the affected system. No known exploits are reported yet.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider restricting access to vulnerable endpoints, applying web application firewalls to detect and block suspicious input, and limiting file permissions to reduce potential impact.