The vulnerability CVE-2026-28011 in ThemeREX Yottis (<= 1.0.10) is caused by improper validation of filenames used in PHP include or require statements. This flaw allows an attacker to perform PHP Local File Inclusion, which can lead to execution of arbitrary code or disclosure of sensitive information. The CVSS v3.1 base score is 8.1, indicating high severity, with network attack vector, high attack complexity, no privileges required, no user interaction, and impacts to confidentiality, integrity, and availability.

Successful exploitation of this vulnerability can lead to unauthorized inclusion of local files, potentially allowing attackers to execute arbitrary code, access sensitive data, or disrupt service availability. The high CVSS score reflects the significant risk to affected systems. However, no active exploits have been reported in the wild so far.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider disabling or restricting the vulnerable functionality if possible, and monitor for updates from ThemeREX regarding patches or mitigations.